Observation, Data Collection and Charting in Industrial Engineering

 

"Notes on Belting" 

Presented at the New York Meeting (December, 1893) of the American Society of Mechanical Engineers, and forming part of Volume XV. of the Transactions.

You can access it from https://archive.org/stream/transactionsof15amer/transactionsof15amer_djvu.txt

pp. 204-259.

125 paragraphs are there in the paper.

The purpose of the paper was to present conclusions to be used in design and use of belting so as to obtain the greatest economy and the most satisfactory results.

It is important to understand carefully the terms "the greatest economy and the most satisfactory results." Taylor always took care to state multiple objectives involved in decision making. The output of a process has to give the most satisfactory results. The customer satisfaction and stakeholder satisfaction especially that of operators involved in the process were always emphasized by Taylor. The greatest economy is to be obtained by assuring first the satisfaction of results. Effectiveness has to be first designed and then only a redesign can be attempted to find lower cost alternative materials, design alternatives and process alternatives.

Important points are extracted from the paper and are given below. Understanding this paper is a foundation to using engineering knowledge to determine the cost collection criteria, cost analysis and redesign of engineering elements to reduce cost.

In using belting so as to obtain the greatest economy and the most satisfactory results, the following rules should be. observed : 

2. The chief consideration has to be the maximum of work from belting cost. Two most important considerations to realize it are securing the minimum of interruptions to manufacture by increasing the durability of the belt to the maximum. This criterion has not hitherto received due attention in belt system design. The one consideration which should have more weight than all others in making up  rules for the use and care of belting is "how to secure the least possible interruption to manufacture from the breakdowns of belts."

3. It is the writer's judgment that belts should be made heavier and run more slowly than theory and accepted rules would indicate, not only for the sake of reducing the belt bill in the long run, but even more to avoid the frequent interruptions to manufacture. In figuring the total expense of belting, and the manufacturing cost chargeable to this account, I think that most careful observers soon come to the conclusion that by far the largest item in this account is the time lost on the machines while belts are being replaced and repaired. This is certainly the case even where the process of manufacture is such that any one machine can be stopped without affecting the running of its neighbors, but far more so in those establishments where the running of a series of machines is dependent one upon another, and the stoppage of one machine involves delays on others. 

4. While working as foreman of a machine shop, the writer became convinced that the belts, which were laced according to the ordinary rules, were a great source of loss to the company — not so much from the cost of the belting and the labor of lacing as from the incidental delays to the machines, and the diminished output of the shop resulting therefrom. The belting was then shown to be by far the largest source of trouble in the shop.

5. But of equal importance in formulating rules for belting is the knowledge of what tension can be surely maintained through a term of  months, or what elements chiefly affect the durability of belting; yet these considerations appear to have been rather neglected by experimenters. Very little information could be obtained either as to the cost of maintenance of belts, or in regard to the interruptions to manufacture from belting, when used under known and uniform conditions as to tension and general treatment.

8. As a result of experience in the old shop, the tight and loose pulleys on the countershafts were made much larger in diameter and of wider face, so that the belt power from main line to countershafting was made about two and one-half times as great as formerly. All belts were made endless by splicing, glueing, and pegging, instead of lacing or hooking, and double belts were used throughout the shop. 

9. In all cases the countershafts were mounted on independent frames, which could be raised and lowered in tightening the belts by the interposition of wooden packing pieces of varying thickness between the frames and the supporting stringers overhead. For this purpose standard packing pieces, varying by eighths of an inch in thickness, were always kept in the tool room. With this method of tightening it was seldom necessary to resplice a belt, since six to ten inches of stretch could be taken up in the belt, by gradually raising the countershaft, before resplicing became necessary. 

10. Belt clamps were used having spring balances between the two pairs of clamps, so that the exact tension to which the belt was subjected was accurately weighed when the belt was first put on, and each time it was tightened. 

11. Experience soon demonstrated about the length of time that each belt would run without requiring to be tightened, and at approximately regular periods the spring-balance belt clamps were put on to each belt and the tension of same weighed, and the countershaft raised just enough to maintain the belt at its proper tension. For this reason, it was a matter of very rare occurrence that a belt slipped during working hours. And as the belts were generally tightened on Sundays (the shop working night and day), the minimum of delay was caused on the machines from this source.

14. At intervals of about three months for the first two years of the test, and after this time at intervals of about five months, each belt was scraped clean, and greased with the kind of dubbing recommended by the maker of the belt. 

15. An accurate account was kept of the original cost of each belt, and every item of expenditure, both for labor and materials used in the maintenance and care of same ; also the exact stretch of each belt was recorded, and its method of treatment throughout (*both engineering details and cost are recorded). 

Taylor's Piece Rate System

Important points and statements are given below.

The advantages of this system of management (Taylor's Piece Rate System) are :

The manufactures are produced cheaper under it.
The system is rapid  in attaining the maximum productivity of each machine and man

The writer has endeavored in the following pages to describe the system of management introduced by him in the works of the Midvale Steel Company, of Philadelphia, which has been employed by them during the past ten years with the most satisfactory results.

The system consists of three principal elements :

( i ) An elementary rate-fixing department.

( 2 ) The differential rate system of piece-work.

( 3 ) What he believes to be the best method of managing men who work by the day.

Elementary rate-fixing differs from other methods of making piece-work prices in that a careful study is made of the time required to do each of the many elementary operations into which the manufacturing of an establishment may be analyzed or divided. These elementary operations are then classified, recorded, and indexed, and when a piece-work price is wanted for work the job is first divided into its elementary operations, the time required to do each elementary operation is found from the records, and the total time for the job is summed up from these data. While this method seems complicated at the first glance, it is, in fact, far simpler and more effective than the old method of recording the time required to do whole jobs of work, and then, after looking over the records of similar jobs, guessing at the time required for any new piece of work.

The advantages of this system of management are :

First. That the manufactures are produced cheaper under it, while at the same time the workmen earn
higher wages than are usually paid.

Second . Since the rate-fixing is done from accurate knowledge instead of more or less by guess-work, the motive for holding back on work, or “ soldiering ”, and endeavoring to deceive the employers as to the time required to do work, is entirely removed, and with it the greatest cause for hard feelings and war between the management and the men.

Third. Since the basis from which piece-work as well as day rates are fixed is that of exact observation, instead of being founded upon accident or deception, as is too frequently the case under ordinary systems, the men are treated with greater uniformity and justice, and respond by doing more and better work.

Fourth, It is for the common interest of both the management and the men to cooperate in every way, so as to turn out each day the maximum quantity and best quality of work.

Fifth. The system is rapid, while other systems are slow, in attaining the maximum productivity of each machine and man ; and when this maximum is once reached, it is automatically maintained by the differential rate.

Sixth. It automatically selects and attracts the best men for each class of work, and it develops many first-class men who would otherwise remain slow or inaccurate, while at the same time it discourages and sifts out men who are incurably lazy or inferior.

Finally. One of the chief advantages derived from the above effects of the system is, that it promotes a most friendly feeling between the men and their employers, and so renders labor unions and strikes unnecessary.

There has never been a strike under the differential rate system of piece-work, although it has been in operation for the past ten years in the steel business, which has been during this period more subject to strikes and labor troubles than almost any other industry. In describing the above system of management the writer has been obliged to refer to other piece-work methods, and to indicate briefly what he believes to be their shortcomings.

2. There is daily more insidious and fatal failure on the part of the superintendents to secure anything even approaching the maximum work from their men and machines.

16. Because no foreman can watch and study all of his men all of the time, and because any system of laying out and apportioning work, and of returns and records, which is sufficiently elaborate to keep proper account of the performance of each workman, is more complicated than piece-work.

40. The remedy for this trouble lies in the establishment in every factory of a proper rate-fixing department; a department which shall have equal dignity and command equal respect with the engineering and managing departments, which shall be organized and conducted in an equally scientific and practical manner.

42. No attempt is made to analyze and time each of the classes of work, or elements of which a job is composed ; although it is a far simpler task to resolve each job into its elements, to make a careful study of the quickest time in which each of the elementary operations can be done, and then to properly classify, tabulate, and index this information, and use it when required for rate-fixing, than it is to fix rates, with even an approximation to justice, under the common system of guessing.

44. Yet this elementary system of fixing rates has been in successful operation for the past ten years, on work complicated in its nature and covering almost as wide a range of variety as any manufacturing that the writer knows of. In 1883, while foreman of the machine shop of the Midvale Steel Company of Philadelphia, it occurred to the writer that it was simpler to time each of the elements of the various kinds of work done in the place, and then find the quickest time in which each job could be done, by summing up the total times of its component parts, than it was to search through the records of former jobs and guess at the proper price. After practising this method of rate-fixing himself for about a year as well as circumstances would permit, it became evident that the system was a success. The writer then established the rate-fixing department, which has given out piece-work prices in the place ever since.

46. Before the best results were finally attained in the case of work done by metal-cutting tools, such as lathes, planers, boring mills, etc., a long and expensive series of experiments was made, to determine, formulate, and finally practically apply to each machine the law governing the proper cutting speed of tools, namely, the effect on the cutting speed of altering any one of the following variables : the shape of the tool (i.e., lip angle, clearance angle, and the line of the cutting edge), the duration of the cut, the quality or hardness of the metal being cut, the depth of the cut, and the thickness of the feed or shaving.

48. As an illustration of the great variety of work to which elementary rate-fixing has already been successfully applied, the writer would state that while acting as general manager of two large sulphite pulp mills he directed the application of piece-work to all of the complicated operations of  manufacturing throughout one of these mills, by means of elementary rate-fixing, with the result, within eighteen months, of more than doubling the output of the mill.

The difference between elementary rate-fixing and the ordinary plan can perhaps be best explained by a simple illustration. Suppose the work to be planing a surface on a piece of cast iron. In the ordinary system the rate-fixer would look through his records of work done by the planing machine, until he found a piece of work as nearly as possible similar to the proposed job, and then guess at the time required to do the new piece of work. Under the elementary system, however, some such analysis as the following would be made :

Work done by Man. Minutes.

Time to lift piece from floor to planer table — - ■

Time to level and set work true on table

Time to put on stops and bolts —

Time to remove stops and bolts

Time to remove piece to floor

Time to clean machine “■

Work done by Machine . Minutes .

Time to rough off cut X in* thick, 4 feet long, 2 X in. wide . t

Time to rough off cut % in. thick, 3 feet long, 12 in. wide etc. -■

Time to finish cut 4 feet long, 2# in. wide

Time to finish cut 3 feet long, 12 in. wide, etc —

Total

Add per cent, for unavoidable delays

It is evident that this job consists of a combination of elementary operations, the time required to do each of which can be readily determined by observation.

This exact combination of operations may never occur again, but elementary operations similar to these will be performed in differing combinations almost every day in the same shop.

A man whose business it is to fix rates soon becomes so familiar with the time required to do each kind of elementary work performed by the men, that he can write down the time from memory.

In the case of that part of the work which is done by the machine, the rate-fixer refers to tables which are made out for each machine, and from which he takes the time required for any combination of breadth, depth, and length of cut

49. While, however, the accurate knowledge of the quickest time in which work can be done, obtained by the rate-fixing department and accepted by the men as standard, is the greatest and most important step toward obtaining the maximum output of the establishment, it is one thing to know how much work can be done in a day and an entirely different matter to get even the best men to work at their fastest speed or anywhere near it.

74. As before stated, not the least of the benefits of elementary rate-fixing are the indirect results.

The careful study of the capabilities of the machines arid the analysis of the speeds at which they must run, before differential rates can be fixed which will insure their maximum output, almost invariably result in first indicating and then correcting the defects in their design and in the method of running and caring for them.

75. In the case of the Midvale Steel Company, to which I have already referred, the machine shop was equipped with standard tools furnished by the best makers, and the study of these machines, such as lathes, planers, boring mills, etc., which was made in fixing rates, developed the fact that they were none of them designed and speeded so as to cut steel to the best advantage. As a result, this company has demanded alterations from the standard in almost every machine which they have bought during the past eight years. They have themselves been obliged to superintend the design of many special tools which would not have been thought of had it not been for elementary rate-fixing.

76. But what is perhaps of more importance still, the rate-fixing department has shown the necessity of carefully systematizing all of the small details in the running of each shop, such as the care of belting, the proper shape for cutting tools, and the dressing, grinding, and issuing sairfe, oiling machines, issuing orders for work, obtaining accurate labor and material returns, and a host of other minor methods and processes. These details, which are usually regarded as of comparatively small importance, and many of which are left to the individual judgment of the foreman and workmen, are shown by the rate-fixing department to be of paramount importance in obtaining the maximum output, and to require the most careful and systematic study and attention in order to insure uniformity and a fair and equal chance for each workman. Without this preliminary study and systematizing of details it is impossible to apply successfully the differential rate in most establishments.

77. As before stated, the success of this system of piece-work depends fundamentally upon the possibility of materially increasing the output per man and per machine, providing the proper man be found for each job and the proper incentive be offered to him.

Time Study - Part 1- F.W. Taylor in Shop Management

 When work is to be repeated many times, the time study should be minute and exact. Each job should be carefully subdivided into its elementary operations, and each of these unit times should receive the most thorough time study. In fixing the times for the tasks, and the piece work rates on jobs of this class, the job should be subdivided into a number of divisions, and a separate time and price assigned to each division rather than to assign a single time and price for the whole job. This should be done for several reasons, the most important of which is that the average workman, in order to maintain a rapid pace, should be given the opportunity of measuring his performance against the task set him at frequent intervals. Many men are incapable of looking very far ahead, but if they see a definite opportunity of earning so many cents by working hard for so many minutes, they will avail themselves of it.

As an illustration, the steel tires used on car wheels and locomotives were originally turned in the Midvale Steel Works on piece work, a single piece-work rate being paid for all of the work which could be done on a tire at a single setting. A fixed price was paid for this work, whether there was much or little metal to be removed, and on the average this price was fair to the men. The apparent advantage of fixing a fair average rate was, that it made rate-fixing exceedingly simple, and saved clerk work in the time, cost and record keeping.

A careful time study, however, convinced the writer that for the reasons given above most of the men failed to do their best. In place of the single rate and time for all of the work done at a setting, the writer subdivided tire-turning into a number of short operations, and fixed a proper time and price, varying for each small job, according to the amount of metal to be removed, and the hardness and diameter of the tire. The effect of this subdivision was to increase the output, with the same men, methods, and machines, at least thirty-three per cent.

As an illustration of the minuteness of this subdivision, an instruction card similar to the one used is reproduced in Figure 1 on the next page. (This card was about 7 inches long by 4 inches wide.)

[Transcriber's note -- Figure 1 not shown]

The cost of the additional clerk work involved in this change was so insignificant that it practically did not affect the problem. This principle of short tasks in tire turning was introduced by the writer in the Midvale Steel Works in 1883 and is still in full use there, having survived the test of over twenty years' trial with a change of management.

In another establishment a differential rate was applied to tire turning, with operations subdivided in this way, by adding fifteen per cent to the pay of each tire turner whenever his daily or weekly piece work earnings passed a given figure.

Time Study - Part 1- F.W. Taylor in Shop Management

In a book of this sort, it would be manifestly impossible to discuss at any length all of the details which go toward making the system a success. Some of them are of such importance as to render at least a brief reference to them necessary. And first among these comes the study of unit times.

This, as already explained, is the most important element of the system advocated by the writer. Without it, the definite, clear-cut directions given to the workman, and the assigning of a full, yet just, daily task,

with its premium for success, would be impossible; and the arch without the keystone would fall to the ground.

n 1883, while foreman of the machine shop of the Midvale Steel Company of Philadelphia, it occurred to the writer that it was simpler to time with a stop watch each of the elements of the various kinds of work done in the place, and then find the quickest time in which each job could be done by summing up the total times of its component parts, than it was to search through the time records of former jobs and guess at the proper time and price. After practicing this method of time study himself for about a year, as well as circumstances would permit, it became evident that the system was a success.

The writer then established the time-study and rate-fixing department, which has given out piece work prices in the place ever since.

This department far more than paid for itself from the very start; but it was several years before the full benefits of the system were felt, owing to the fact that the best methods of making and recording time observations, as well as of determining the maximum capacity of each of the machines in the place, and of making working tables and time tables, were not at first adopted.

It has been the writer's experience that the difficulties of scientific time study are underestimated at first, and greatly overestimated after actually trying the work for two or three months. The average manager who decides to undertake the study of unit times in his works fails at first to realize that he is starting a new art or trade. He understands, for instance, the difficulties which he would meet with in establishing a drafting room, and would look for but small results at first, if he were to give a bright man the task of making drawings, who had never worked in a drafting room, and who was not even familiar with drafting implements and methods, but he entirely underestimates the difficulties of this new trade.

The art of studying unit times is quite as important and as difficult as that of the draftsman. It should be undertaken seriously, and looked upon as a profession. It has its own peculiar implements and methods, without the use and understanding of which progress will necessarily be slow, and in the absence of which there will be more failures than successes scored at first.

When, on the other hand, an energetic, determined man goes at time study as if it were his life's work, with the determination to succeed, the results which he can secure are little short of astounding. The difficulties of the task will be felt at once and so strongly by any one who undertakes it, that it seems important to encourage the beginner by giving at least one illustration of what has been  accomplished.

Mr. Sanford E. Thompson, C. E., started in 1896 with but small help from the writer, except as far as the implements and methods are concerned, to study the time required to do all kinds of work in the building trades. In six years he has made a complete study of eight of the most important trades--excavation, masonry (including sewer-work and paving), carpentry, concrete and cement work, lathing and plastering, slating and roofing and rock quarrying. He took every stop watch observation himself and then, with the aid of two comparatively cheap assistants, worked up and tabulated all of his data ready for the printer. The magnitude of this undertaking will be appreciated when it is understood that the tables and descriptive matter for one of these trades alone take up about 250 pages. Mr. Thompson and the writer are both engineers, but neither of us was especially familiar with the above trades, and this work could not have been accomplished in a lifetime without the study of elementary units with a stop watch.

In the course of this work, Mr. Thompson has developed what are in many respects the best implements in use, and with his permission some of them will be described. The blank form or note sheet used by Mr. Thompson, contains essentially:

(1) Space for the description of the work and notes in regard to it.

(2) A place for recording the total time of complete operations--that is, the gross time including all necessary delays, for doing a whole job or large portions of it.

(3) Lines for setting down the "detail operations, or units" into which any piece of work may be divided, followed by columns for entering the averages obtained from the observations.

(4) Squares for recording the readings of the stop watch when observing the times of these elements. If these squares are filled, additional records can be entered on the back. The size of the sheets, which should be of best quality ledger paper, is 8 3/4 inches wide by 7 inches long, and by folding in the center they can be conveniently carried in the pocket, or placed in a case (see Fig. 3, page 153) containing one or more stop watches.

This case, or "watch book," is another device of Mr. Thompson's. It consists of a frame work, containing concealed in it one, two, or three watches, whose stop and start movements can be operated by pressing with the fingers of the left hand upon the proper portion of the cover of the note-book without the knowledge of the workman who is being observed. The frame is bound in a leather case resembling a pocket note-book, and has a place for the note sheets described.

The writer does not believe at all in the policy of spying upon the workman when taking time observations for the purpose of time study. If the men observed are to be ultimately affected by the results of these observations, it is generally best to come out openly, and let them know that they are being timed, and what the object of the timing is. There are many cases, however, in which telling the workman that he was being timed in a minute way would only result in a row, and in defeating the whole object of the timing; particularly when only a few time units are to be studied on one man's work, and when this man will not be personally affected by the results of the observations. In these cases, the watch book of Mr. Thompson, holding the watches in the cover, is especially useful. A good deal of judgment is required to know when to time openly, or the reverse.

The operation selected for illustration on the note sheet shown in Fig. 2, page 151, is the excavation of earth with wheelbarrows, and the values given are fair averages of actual contract work where the

wheelbarrow man fills his own barrow. It is obvious that similar methods of analyzing and recording may be applied to work ranging from unloading coal to skilled labor on fine machine tools.

The method of using the note sheets for timing a workman is as follows:

After entering the necessary descriptive matter at the top of the sheet, divide the operation to be timed into its elementary units, and write these units one after another under the heading "Detail operations." If the job is long and complicated, it may be analyzed while the timing is going on, and the elementary units entered then instead of beforehand.

In wheelbarrow work as illustrated in the example shown on the note sheet, the elementary units consist of "filling barrow," "starting" (which includes throwing down shovel and lifting handles of barrow), "wheeling full," etc. These units might have been further subdivided--the first one into time for loading one shovelful, or still further into the time for filling and the time for emptying each shovelful. The letters a, b, c, etc., which are printed, are simply for convenience in designating the elements.

We are now ready for the stop watch, which, to save clerical work, should be provided with a decimal dial similar to that shown in Fig. 4. The method of using this and recording the times depends upon the character of the time observations. In all cases, however, the stop watch times are recorded in the columns headed "Time" at the top of the right-hand half of the note sheet. These columns are the only place on the face of the sheet where stop watch readings are to be entered. If more space is required for these times, they should be entered on the back of the sheet. The rest of the figures (except those on the left-hand side of the note sheet, which may be taken from an ordinary timepiece) are the results of calculation, and may be made in the office by any clerk.

As has been stated, the method of recording the stop watch observations depends upon the work which is being observed. If the operation consists of the same element repeated over and over, the time of each may be set down separately; or, if the element is very small, the total time of, say, ten may be entered as a fraction, with the time for all ten observations as the numerator, and the number of observations for the denominator.

In the illustration given on the note sheet, Fig. 2, the operation consists of a series of elements. In such a case, the letters designating each elementary unit are entered under the columns "Op.," the stop watch is thrown to zero, and started as the man commences to work. As each new division of the operation (that is, as each elementary unit or unit time) is begun, the time is recorded. During any special delay the watch may be stopped, and started again from the same point, although, as a rule, Mr. Thompson advocates allowing the watch to run continuously, and enters the time of such a stop, designating it for convenience by the letter "Y."

In the case we are considering, two kinds of materials were handled sand and clay. The time of each of the unit times, except the "filling," is the same for both sand and clay; hence, if we have sufficient
observations on either one of the materials, the only element of the other which requires to be timed is the loading. This illustrates one of the merits of the elementary system.

The column "Av." is filled from the preceding column. The figures thus found are the actual net times of the different unit times. These unit times are averaged and entered in the "Time" column, on the lower half of the right-hand page, preceded, in the "No." column, by the number of observations which have been taken of each unit. These times, combined and compared with the gross times on the left-hand page, will determine the percentage lost in resting and other necessary delays. A convenient method for obtaining the time of an operation, like picking, in which the quantity is difficult to measure, is suggested by the records on the left-hand page.

The percentage of the time taken in rest and other necessary delays, which is noted on the sheet as, in this case, about 27 per cent, is obtained by a comparison of the average net "time per barrow" on the
right with the "time per barrow" on the left. The latter is the quotient of the total time shoveling and wheeling divided by the number of loads wheeled.

It must be remembered that the example given is simply for illustration. To obtain accurate average times, for any item of work under specified conditions, it is necessary to take observations upon a number of men, each of whom is at work under conditions which are comparable. The total number of observations which should be taken of any one elementary unit depends upon its variableness, and also upon its frequency of occurrence in a day's work.

An expert observer can, on many kinds of work, time two or three men at the same time with the same watch, or he can operate two or three watches--one for each man. A note sheet can contain only a comparatively few observations. It is not convenient to make it of larger size than the dimensions given, when a watch-book is to be used, although it is perfectly feasible to make the horizontal rulings 8 lines to the inch instead of 5 lines to the inch as on the sample sheet. There will have to be, in almost all cases, a large number of note sheets on the same subject. Some system must be arranged for collecting and tabulating these records. On Tables 2A and 2B (pages 160 and 161) is shown the form used for tabulating. The length should be either 17 or 22 inches. The height of the form is 11 inches. With these dimensions a form may be folded and filed with ordinary letter sheets (8 1/2 inches by 11 inches). The ruling which has been found most convenient is for the vertical divisions 3 columns to 1 1/8 inches, while the horizontal lines are ruled 6 to the inch. The columns may, or may not, have printed headings.

The data from the note sheet in Fig. 2 (page 151) is copied on to the table for illustration. The first columns of the table are descriptive. The rest of them are arranged so as to include all of the unit times, with any other data which are to be averaged or used when studying the results. At the extreme right of the sheet the gross times, including rest and necessary delay, are recorded and the percentages of rest are calculated.

Formulae are convenient for combining the elements. For simplicity, in the example of barrow excavation, each of the unit times may be designated by the same letters used on the note sheet (Fig. 2) although in practice each element can best be designated .by the initial letters of the words describing it.

Let

a = time filling a barrow with any material.

b = time preparing to wheel.

c = time wheeling full barrow 100 feet.

d = time dumping and turning.

e = time returning 100 feet with empty barrow.

f = time dropping barrow and starting to shovel.

p = time loosening one cubic yard with the pick.

P = percentage of a day required to rest and necessary delays.

L = load of a barrow in cubic feet.

B = time per cubic yard picking, loading, and wheeling any given kind of earth to any given distance when the wheeler loads his own barrow.

[Transcriber's note -- formula  and Tables omitted]

This general formula for barrow work can be simplified by choosing average values for the constants, and substituting numerals for the letters now representing them. Substituting the average values from the note sheet on Fig. 2 (page 151), our formula becomes:
[Transcriber's note -- formula omitted]

In classes of work where the percentage of rest varies with the different elements of an operation it is most convenient to correct all of the elementary times by the proper percentages before combining them. Sometimes after having constructed a general formula, it may be solved by setting down the substitute numerical values in a vertical column for direct addition.

Table 3 (page 164) gives the times for throwing earth to different distances and different heights. It will be seen that for each special material the time for filling shovel remains the same regardless of the distance to which it is thrown. Each kind of material requires a different time for filling the shovel. The time throwing one shovelful, on the other hand, varies with the length of throw, but for any given distance it is the same for all of the earths. If the earth is of such a nature that it sticks to the shovel, this relation does not hold. For the elements of shoveling we have therefore:

s = time filling shovel and straightening up ready to throw.

t = time throwing one shovelful.

w = time walking one foot with loaded shovel.

w1 = time returning one foot with empty shovel.

L = load of a shovel in cubic feet.

P = percentage of a day required for rest and necessary delays.

T = time for shoveling one cubic yard.

Our formula, then, for handling any earth after it is loosened, is:
[Transcriber's note -- omitted]

Where the material is simply thrown without walking, the formula becomes:

If weights are used instead of volumes:
[Transcriber's note -- omitted]

The writer has found the printed form shown on the insert, Fig. 5 (opposite page 166), useful in studying unit times in a certain class of the hand work done in a machine shop. This blank is fastened to a thin board held in the left hand and resting on the left arm of the observer. A stop watch is inserted in a small compartment attached to the back of the board at a point a little above its center, the face of the watch being seen from the front of the board through a small flap cut partly loose from the observation blank. While the watch is operated by the fingers of the left hand, the right hand of the operator is at all times free to enter the time observations on the blank. A pencil sketch of the work to be observed is made in the blank space on the upper left-hand portion of the sheet. In using this blank, of course, all attempt at secrecy is abandoned.

The mistake usually made by beginners is that of failing to note in sufficient detail the various conditions surrounding the job. It is not at first appreciated that the whole work of the time observer is useless if there is any doubt as to even one of these conditions. Such items, for instance, as the name of the man or men on the work, the number of helpers, and exact description of all of the implements used, even those which seem unimportant, such, for instance, as the diameter and length of bolts and the style of clamps used, the weight of the piece upon which work is being done, etc.

It is also desirable that, as soon as practicable after taking a few complete sets of time observations, the operator should be given the opportunity of working up one or two sets at least by summing up the unit times and allowing the proper per cent of rest, etc., and putting them into practical use, either by comparing his results with the actual time of a job which is known to be done in fast time, or by setting a time which a workman is to live up to.

The actual practical trial of the time student's work is most useful, both in teaching him the necessity of carefully noting the minutest details, and on the other hand convincing him of the practicability of
the whole method, and in encouraging him in future work.

In making time observations, absolutely nothing should be left to the memory of the student. Every item, even those which appear self-evident, should be accurately recorded. The writer, and the assistant who immediately followed him, both made the mistake of not putting the results of much of their time study into use soon enough, so that many times observations which extended over a period of months were thrown away, in most instances because of failure to note some apparently unimportant detail.

It may be needless to state that when the results of time observations are first worked up, it will take far more time to pick out and add up the proper unit times, and allow the proper percentages of rest, etc., than it originally did for the workman to do the job. This fact need not disturb the operator, however. It will be evident that the slow time made at the start is due to his lack of experience, and he must take it for granted that later many short-cuts can be found, and that a man with an average memory will be able with practice to carry all of the important time units in his head.

No system of time study can be looked upon as a success unless it enables the time observer, after a reasonable amount of study, to predict with accuracy how long it should take a good man to do almost any job in the particular trade, or branch of a trade, to which the time student has been devoting himself. It is true that hardly any two jobs in a given trade are exactly the same and that if a time student were to follow the old method of studying and recording the whole time required to do the various jobs which came under his observation, without dividing them into their elements, he would make comparatively small progress in a lifetime, and at best would become a skillful guesser. It is, however, equally true that all of the work done in a given trade can be divided into a comparatively small number of elements or units, and that with proper implements arid methods it is comparatively easy for a skilled observer to determine the time required by a good man to do any one of these elementary units.

Having carefully recorded the time for each of these elements, it is a simple matter to divide each job into its elementary units, and by adding their times together, to arrive accurately at the total time for
the job. The elements of the art which at first appear most difficult to investigate are the percentages which should be allowed, under different conditions, for rest and for accidental or unavoidable delays. These elements can, however, be studied with about the same accuracy as the others.

Perhaps the greatest difficulty rests upon the fact that no two men work at exactly the same speed. The writer has found it best to take his time observations on first-class men only, when they can be found; and these men should be timed when working at their best. Having obtained the best time of a first-class man, it is a simple matter to determine the percentage which an average man will fall short of this maximum.

It is a good plan to pay a first-class man an extra price while his work is being timed. When work men once understand that the time study is being made to enable them to earn higher wages, the writer has found them quite ready to help instead of hindering him in his work. The division of a given job into its proper elementary units, before beginning the time study, calls for considerable skill and good judgment. If the job to be observed is one which will be repeated over and over again, or if it is one of a series of similar jobs which form an important part of the standard work of an establishment, or of the trade which is being studied, then it is best to divide the job into elements which are rudimentary. In some cases this subdivision should be carried to a point which seems at first glance almost absurd.

For example, in the case of the study of the art of shoveling earths, referred to in Table 3, page 164, it will be seen that handling a shovelful of dirt is subdivided into, s = "Time filling shovel and
straightening up ready to throw," and t = "Time throwing one shovelful."

The first impression is that this minute subdivision of the work into elements, neither of which takes more than five or six seconds to perform, is little short of preposterous; yet if a rapid and thorough time study of the art of shoveling is to be made, this subdivision simplifies the work, and makes time study quicker and more thorough.

The reasons for this are twofold:

First. In the art of shoveling dirt, for instance, the study of fifty or sixty small elements, like those referred to above, will enable one to fix the exact time for many thousands of complete jobs of shoveling, constituting a very considerable proportion of the entire art.

Second. The study of single small elements is simpler, quicker, and more certain to be successful than that of a large number of elements combined. The greater the length of time involved in a single item of time study, the greater will be the likelihood of interruptions or accidents, which will render the results obtained by the observer questionable or even useless.

There is a considerable part of the work of most establishments that is not what may be called standard work, namely, that which is repeated many times. Such jobs as this can be divided for time study into groups, each of which contains several rudimentary elements. A division of this sort will be seen by referring to the data entered on face of note sheet, Fig. 2 (page 151).

In this case, instead of observing, first, the "time to fill a shovel," and then the time to "throw it into a wheelbarrow," etc., a number of these more rudimentary operations are grouped into the single operation of

a = "Time filling a wheelbarrow with any material."

This group of operations is thus studied as a whole.

Another illustration of the degree of subdivision which is desirable will be found by referring to the inserts, Fig. 5 (opposite page 166).

Where a general study is being made of the time required to do all kinds of hand work connected with and using machine tools, the items printed in detail should be timed singly.

When some special job, not to be repeated many times, is to be studied, then several elementary items can be grouped together and studied as a whole, in such groups for example as:

(a) Getting job ready to set.

(b) Setting work.

(c) Setting tool.

(d) Extra hand work.

(e) Removing work.

And in some cases even these groups can be further condensed.

An illustration of the time units which it is desirable to sum up and properly record and index for a certain kind of lathe work is given in Fig. 6.

The writer has found that when some jobs are divided into their proper elements, certain of these elementary operations are so very small in time that it is difficult, if not impossible, to obtain accurate

readings on the watch. In such cases, where the work consists of recurring cycles of elementary operations, that is, where a series of elementary operations is repeated over and over again, it is possible to take sets of observations on two or more of the successive elementary operations which occur in regular order, and from the times thus obtained to calculate the time of each element. An example of this is the work of loading pig iron on to bogies. The elementary operations or elements consist of:

(a) Picking up a pig.

(b) Walking with it to the bogie.

(c) Throwing or placing it on the bogie.

(d) Returning to the pile of pigs.

Here the length of time occupied in picking up the pig and throwing or placing it on the bogie is so small as to be difficult to time, but observations may be taken successively on the elements in sets of three.

We may, in other words, take one set of observations upon the combined time of the three elements numbered 1, 2, 3; another set upon elements 2, 3, 4; another set upon elements, 3, 4, 1, and still another upon the set 4,1, 2. By algebraic equations we may solve the values of each of the separate elements.

If we take a cycle consisting of five (5) elementary operations, a, b, c, d, e, and let observations be taken on three of them at a time, we have the equations:

[Transcriber's Note: omitted]

The writer was surprised to find, however, that while in some cases these equations were readily solved, in others they were impossible of solution. My friend, Mr. Carl G. Barth, when the matter was referred to him, soon developed the fact that the number of elements of a cycle which may be observed together is subject to a mathematical law, which is expressed by him as follows:

The number of successive elements observed together must be prime to the total number of elements in the cycle.

Namely, the number of elements in any set must contain no factors; that is, must be divisible by no numbers which are contained in the total number of elements. The following table is, therefore, calculated by Mr. Barth showing how many operations may be observed together in various

cases. The last column gives the number of observations in a set which will lead to the determination of the results with the minimum of labor.

[Transcriber's note -- Table omitted]

When time study is undertaken in a systematic way, it becomes possible to do greater justice in many ways both to employers and workmen than has been done in the past. For example, we all know that the first time that even a skilled workman does a job it takes him a longer time than is required after he is familiar with his work, and used to a particular sequence of operations. The practiced time student can not only figure out the time in which a piece of work should be done by a good man, after he has become familiar with this particular job through practice, but he should also be able to state how much more time would be required to do the same job when a good man goes at it for the first time; and

this knowledge would make it possible to assign one time limit and price for new work, and a smaller time and price for the same job after being repeated, which is much more fair and just to both parties than the usual fixed price.

As the writer has said several times, the difference between the best speed of a first-class man and the actual speed of the average man is very great. One of the most difficult pieces of work which must be faced by the man who is to set the daily tasks is to decide just how hard it is wise for him to make the task. Shall it be fixed for a first-class man, and if not, then at what point between the first-class and the

average? One fact is clear, it should always be well above the performance of the average man, since men will invariably do better if a bonus is offered them than they have done without this incentive. The

writer has, in almost all cases, solved this part of the problem by fixing a task which required a first-class man to do his best, and then offering a good round premium. When this high standard is set it takes

longer to raise the men up to it. But it is surprising after all how rapidly they develop.

The precise point between the average and the first-class, which is selected for the task, should depend largely upon the labor market in which the works is situated. If the works were in a fine labor market, such, for instance, as that of Philadelphia, there is no question that the highest standard should be aimed at. If, on the other hand, the shop required a good deal of skilled labor, and was situated in a small country town, it might be wise to aim rather lower. There is a great difference in the labor markets of even some of the adjoining states in this country, and in one instance, in which the writer was aiming at a high standard in organizing a works, he found it necessary to import almost all of his men from a neighboring state before meeting with success.

Whether the bonus is given only when the work is done in the quickest time or at some point between this and the average time, in all cases the instruction card should state the best time in which the work can be done by a first-class man. There will then be no suspicion on the part of the men when a longer "bonus time" is allowed that the time student does not really know the possibilities of the case. For example, the instruction card might read:

Proper time . . . . . 65 minutes

Bonus given first time job is done. 108 minutes

It is of the greatest importance that the man who has charge of assigning tasks should be perfectly straightforward in all of his dealings with the men. Neither in this nor in any other branch of the

management should a man make any pretense of having more knowledge than he really possesses. He should impress the workmen with the fact that he is dead in earnest, and that he fully intends to know all about it some day; but he should make no claim to omniscience, and should always be ready to acknowledge and correct an error if he makes one. This combination of determination and frankness establishes a sound and healthy relation between the management and men.

There is no class of work which cannot be profitably submitted to time study, by dividing it into its time elements, except such operations as take place in the head of the worker; and the writer has even seen a time study made of the speed of an average and first-class boy in solving problems in mathematics.

Clerk work can well be submitted to time study, and a daily task assigned in work of this class which at first appears to be very miscellaneous in its character.

One of the needs of modern management is that of literature on the subject of time study. The writer quotes as follows from his paper on "A Piece Rate System," written in 1895:

"Practically the greatest need felt in an establishment wishing to start a rate-fixing department is the lack of data as to the proper rate of speed at which work should be done. There are hundreds of operations which are common to most large establishments, yet each concern studies the speed problem for itself, and days of labor are wasted in what should be settled once for all, and recorded in a form which is available to all manufacturers.

"What is needed is a hand-book on the speed with which work can be done, similar to the elementary engineering handbooks. And the writer ventures to predict that such a book will before long be forthcoming. Such a book should describe the best method of making, recording, tabulating, and

indexing time observations, since much time and effort are wasted by the adoption of inferior methods."

Unfortunately this prediction has not yet been realized. The writer's chief object in inducing Mr. Thompson to undertake a scientific time study of the various building trades and to join him in a publication of this work was to demonstrate on a large scale not only the desirability of accurate time study, but the efficiency and superiority of the method of studying elementary units as outlined above. He trusts that his object may be realized and that the publication of this book may be followed by similar works on other trades and more particularly on the details of machine shop practice, in which he is especially interested.

Machine Tool Time Estimation Methods

Methods employed in solving the time problem for machine tools.

As a machine shop has been chosen to illustrate the application of such details of scientific management as time study, the planning department, functional foremanship, instruction cards, etc., the description would be far from complete without at least a brief reference to the methods employed in solving the time problem for machine tools.

Methods employed in solving the time problem for machine tools

The study of this subject involved the solution of four important problems:

First. The power required to cut different kinds of metals with tools of various shapes when using different depths of cut and coarseness of feed, and also the power required to feed the tool under varying conditions.

Second. An investigation of the laws governing the cutting of metals with tools, chiefly with the object of determining the effect upon the best cutting speed of each of the following variables:

(a) The quality of tool steel and treatment of tools (i.e., in heating, forging, and tempering them).

(b) The shape of tool (i.e., the curve or line of the cutting edge, the lip angle, and clearance angle)

(c) The duration of cut or the length of time the tool is required to last before being re-ground.

(d) The quality or hardness of the metal being cut (as to its effect on cutting speed).

(e) The depth of the cut.

(f) The thickness of the feed or shaving

(g) The effect on cutting speed of using water or other cooling medium on the tool.

Third. The best methods of analyzing the driving and feeding power of machine tools and, after considering their limitations as to speeds and feeds, of deciding upon the proper counter-shaft or other general driving speeds.

Fourth. After the study of the first, second, and third problems had resulted in the discovery of certain clearly defined laws, which were expressed by mathematical formulae, the last and most difficult task of all lay in finding a means for solving the entire problem which should be so practical and simple as to enable an ordinary mechanic to answer quickly and accurately for each machine in the shop the question, "What driving speed, feed, and depth of cut will in each particular case do the work in the quickest time?"

In 1881, in the machine shop of the Midvale Steel Company, the writer began a systematic study of the laws involved in the first and second problems above referred to by devoting the entire time of a large vertical boring mill to this work, with special arrangements for varying the drive so as to obtain any desired speed. The needed uniformity of the metal was obtained by using large locomotive tires of known chemical composition, physical properties and hardness, weighing from 1,500 to 2,000 pounds.

For the greater part of the succeeding 22 years these experiments were carried on, first at Midvale and later in several other shops, under the general direction of the writer, by his friends and assistants, six machines having been at various times especially fitted up for this purpose.

The exact determination of these laws and their reduction to formulae have proved a slow but most interesting problem; but by far the most difficult undertaking has been the development of the methods and finally the appliances (i.e., slide rules) for making practical use of these laws after they were discovered.

In 1884 the writer succeeded in making a slow solution of this problem with the help of his friend, Mr. Geo. M. Sinclair, by indicating the values of these variables through curves and laying down one set of curves over another. Later my friend, Mr. H. L. Gantt, after devoting about 1 1/2 years exclusively to this work, obtained a much more rapid and simple solution. It was not, however, until 1900, in the works of the Bethlehem Steel Company, that Mr. Carl G. Barth, with the assistance of Mr. Gantt and a small amount of help from the writer, succeeded in developing a slide rule by means of which the entire problem can be accurately and quickly solved by any mechanic.

The difficulty from a mathematical standpoint of obtaining a rapid and accurate solution of this problem will be appreciated when it is remembered that twelve independent variables enter into each problem, and that a change in any of these will affect the answer. The instruction card can be put to wide and varied use. It is to the art of management what the drawing is to engineering, and, like the latter, should vary in size and form according to the amount and variety of the information which it is to convey. In some cases it should consist of a pencil memorandum on a small piece of paper which will be sent directly to the man requiring the instructions, while in others it will be in the form of several pages of typewritten matter, properly varnished and mounted, and issued under the check or other record system, so that it can be used time after time. A description of an instruction card of this kind may be useful.

After the writer had become convinced of the economy of standard methods and appliances, and the desirability of relieving the men as far as possible from the necessity of doing the planning, while master mechanic at Midvale, he tried to get his assistant to write a complete instruction card for overhauling and cleaning the boilers at regular periods, to be sure that the inspection was complete, and that while the work was thoroughly done, the boilers should be out of use as short a time as possible, and also to have the various elements of this work done on piece work instead of by the day. His assistant, not having undertaken work of this kind before, failed at it, and the writer was forced to do it himself. He did all of the work of chipping, cleaning, and overhauling a set of boilers and at the same time made a careful time study of each of the elements of the work. This time study showed that a great part of the time was lost owing to the constrained position of the workman. Thick pads were made to fasten to the elbows, knees, and hips; special tools and appliances were made for the various details of the work; a complete list of the tools and implements was entered on the instruction card, each tool being stamped with its own number for identification, and all were issued from the tool room in a tool box so as to keep them together and save time. A separate piece work price was fixed for each of the elements of the job and a thorough inspection of each part of the work secured as it was completed.

The instruction card for this work filled several typewritten pages, and described in detail the order in which the operations should be done and the exact details of each man's work, with the number of each tool required, piece work prices, etc.

The whole scheme was much laughed at when it first went into use, but the trouble taken was fully justified, for the work was better done than ever before, and it cost only eleven dollars to completely overhaul a set of 300 H.P. boilers by this method, while the average cost of doing the same work on day work without an instruction card was sixty-two dollars.

Process Chart Method  - Gilbreths - 1921

Happy to See the caption. 

"In celebrating 100 years to the presentation of the process charts" 

in  "Moshe Eben-Chaime (2022) On the relationships between the design of assembly manufacturing and inspection systems and product quality," IISE Transactions, 54:3,227-237. 

DOI: 10.1080/24725854.2021.1905196

Link to this article: https://doi.org/10.1080/24725854.2021.1905196

Process Chart Method  - Gilbreths - 1921

Process Charts for Recording and Visualizing Processes in Industrial Engineering.

Process charts are the recording devices used by industrial engineers. 

Gilbreth used process charts and described them for wider audience in 1921. 

In the original description, Gilbreth described the process charts used in connection with motion study or human effort study. Later the scope of the process charts was extended and the contents of the chart were standardized by ASME.  Operation analysis sheet was used  by Maynard and Stegemerten in the process chart framework to do machine work study. 

In the process chart, five operations are depicted. They are: Operation (material processing) - Inspection - Material transport - Temporary Storage of the Material (Delay without any operation being done) - Permanent or controlled storage of the material.

Each operation has a cost and industrial engineer has to increase the productivity of each operation or step to reduce cost.

In each operations, machines, men and other facilities work to bring the desired result. The work of machines, men, robots, furnaces etc. are to be observed, studies and recorded. To study work of operators, Motion study of both hands and micromotion studies of both hands were developed by   by Gilbreths.  The process chart that shows the series of operations is further supported charts related to each operation that record activity of each machine and man working in that operation. To do detailed investigation based on process chart, more recording formats need to be used. There is a need for machine work study and operator work study in each of the five steps shown in the flow process chart. Recording devices are to be used machine and operator work studies in each step.  Value Adding Operation, Inspection, Transport, Temporary Delay and Permanent Delay. Frank Gilbreth is given credit for the development of process chart system in industrial engineering to study and improve processes.

Process Charting for Improvement - Gilbreths' View

Frank Gilbreth developed process analysis and improvement also along with motion study. In 1921, he presented a paper in ASME, on process charts. Lilian Gilbreth was a coauthor of this paper.

PROCESS CHARTS: FIRST STEPS IN FINDING THE ONE BEST WAY TO DO WORK
By Frank B. Gilbreth, Montclair, N. J. Member of the Society
and L. M. Gilbreth, Montclair, N. J. Non-Member
For presentation at the Annual Meeting, New York, December 5 to 9, 1921,
of The American Society of Mechanical Engineers, 29 West 39th Street, New York.
https://ia800700.us.archive.org/5/items/processcharts00gilb/processcharts00gilb_bw.pdf

THE Process Chart is a device for visualizing a process as a means of improving it. Every detail of a process is more or less affected by every other detail; therefore the entire process must be presented in such form that it can be visualized all at once before any changes are made in any of its subdivisions. In any subdivision of the process under examination, any changes made without due consideration of all the decisions and all the motions that precede and follow that subdivision will often be found unsuited to the ultimate plan of operation.

The use of this process-chart procedure permits recording the existing and proposed methods and changes without the slightest fear of disturbing or disrupting the actual work itself.

The aim of the process chart is to present information regarding existing and proposed processes in such simple form that such information can become available to and usable by the greatest possible number of people in an organization before any changes whatever are actually made, so that the special knowledge and suggestions of those in positions of minor importance can be fully utilized.

Further detailed studies based on process chart

If any operation of the process shown in the process chart is one that will sufficiently affect similar work, then motion study (human effort study) should be made of each part of the process, and the degree to which the motion study should be carried depends upon the opportunities existing therein for savings.

If the operations are highly repetitive or consist of parts or subdivisions that can be transferred to the study of many other operations, then micromotion studies already made can be referred to; also new and further micromotion studies may be warranted in order that the details of method with the exact times of each of the individual subdivisions of the cycle of motions, or ''therbligs," as they are called, that compose the one best way known, may be recorded for constant and cumulative improvement.

These synthesized records of details of processes (motion studies and micromotion studies) in turn may be further combined and large units of standard practice become available for the synthesis of complete operations in process charts.

Similarly we have to add that if an operation is done or repeated multiple times, machine effort study or machine work study needs to be done and work of the machine has to be recorded using a format used in process planning of the machine.

At the end of the paper, the conclusion made by Gilbreths is as follows:

The procedure for making, examining and improving a process is, therefore, preferably as follows:

a.  Examine process and record with rough notes,  the existing process in detail.

b. Have draftsman copy rough notes in form for blueprinting, stereoscopic diapositives, photographic projection and exhibition to executives and others.

c. Show the diapositives with stereoscope and lantern slides of process charts in executives' theater to executives and workers.

d. Improve present methods by the use of —
1 Suggestion system

2 Motion study
3 Micromotion studies and chronocyclegraphs for obtaining and recording the One Best Way to do Work.
4 Written description of new methods or 'write-ups," "manuals," ''codes," ''written systems," as they are variously called
5 Standards
6 Standing orders

e. Make process chart of the process as finally adopted as a base for still further and cumulative improvement.

We have to add now machine work study to the list of activities of examining process charts for process industrial engineering (We will discuss each step or operation of the process chart in forthcoming lessons in detail)

We see in the method described above the method study steps of record, and examine. The practice of involving the workers in analyzing the process chart which was later popularized by Alan Mogensen is also present in the method suggested by Gilbreth to improve a process.  Motion study as a later step in the process analysis method, which was emphasized by H.B. Maynard as part of the operation analysis proposed by him is also visible in the procedure described by Gilbreths.

H.B. Maynard proposed "Operation Analysis" for process improvement.

So, we can see the methods engineering and methods study which became popular subsequently were further development of Gilbreth's process improvement procedure only.

ASME - Gilbreth Process Chart

Gilbreth proposed summarizing the data recorded on a process into process chart for providing the comprehensive starting point for process analysis for productivity improvement. Each step shown in the process has addition charts and data associated with it for detailed study and analysis by the productivity analysis and improvement team. Recording of data and preparation of process chart can be done by a limited number of persons. But productivity analysis team can be big and also they can be displayed so that more number of persons in the organization provide their suggestions for productivity improvement.

ASME appointed a committee to standardize the chart and the committee recommended the following steps.

Operation (Processing: Material Processing) -  Inspection - Transportation - Delays - Storage

Each step has engineering knowledge and management (planning and control) knowledge associated with it. To do engineering process improvement for productivity, basic engineering knowledge and basic management knowledge are required.

In the area of manufacturing and machinery operation processes we can see the requirement of following subjects.

Material processing or machinery operation - Manufacturing processes, machinery operations manuals (For example hydraulic machinery, automobile engineering)

Inspection: Drawings, Specifications, Metrology and Measurement, Automated inspection

Transportation: Factory layout, Work station layout, Manual handling, Mechanical handling, Automated handling

Delays - Production quantity planning and control, Project planning and control,  Maintenance, Rework

Storage: Storing parts, subassemblies, picking, kitting, issue procedures (Warehouse design, operation and management)

Process Industrial Engineering uses the process charts as the primary visualization devices for examining processes for industrial engineering (productivity engineering) them. The analysis of industrial engineering for process productivity improvement goes up to the lowest level like tool angles of a cutting tool. But the comprehensive process industrial engineering of a process begins by the creation of the process chart and its examination by each operation. That way to complete process is analysis without missing any operation.

The Operation Analysis Sheet

A form known as the " analysis sheet" has been designed by the Methods Engineering Council. In the form information related to all the relevant elements related to work of machines and operators, and elements of machines and elements related to men are recorded. The elements related to machines are collected from process plans as specified elements and are observed and recorded to document the actual practice. Similarly manual elements are also collected from the standard instruction sheets, actual practice is observed and recorded.

At the top of the form on the front side, space is provided for identifying completely the analysis, the part, and the operation.


1. Operation Information  and Purpose of Operation.

Item 1.  The first point considered is the purpose of the operation. If analysis shows that the operation serves a definite purpose, various other means of accomplishing the same result are considered to see if a better way can be found.

2. Product Design, Tolerances and Inspection Requirements.

Item. 2. The  specification and tolerance requirements of the job must be looked into thoroughly, for the accuracy required has a direct bearing on the methods used to produce the work. The analyst should consider it his duty to investigate them in order to satisfy himself as to their necessity. Occasionally, tolerance  requirements are hurriedly and incorrectly established, and a subsequent check will bring this to light. Usually, the requirements err in the direction of unnecessary accuracy; for if the requirements are too loose, the part will not function properly in the final assembly and the error will be caught. Occasionally, however, the analyst will find that if the requirements are made more exacting on one operation, a subsequent operation will be made easier to perform.

3. Material.

Item 3. The material for the part being studied  is specified by the design engineer.  Design engineers, are not infallible and sometimes specify an unnecessarily costly material. It is proper and necessary that the methods engineer should check on the cost aspect of the material and point out them to initiate redesign. 

In other cases, certain materials present shop difficulties and based on that information industrial engineer has to initiate redesign work.  A certain cheap, brittle material may be so difficult to machine that an excessive amount of scrap results. Here investigation might show that it would be less expensive in the end to specify a more costly but more easily machined material.

4. Process Sequence and Operation Division Analysis

Item 4. If operation or flow process charts have not been constructed first, all the operations performed on the part are  listed in the analysis sheet. The purpose of this is to determine just how the operation being analyzed fits in with the other operations that are performed on the part. This study frequently brings to light the fact that the operation being analyzed can be eliminated altogether or that, by combining it with other operations or performing it during the idle period of another operation, the time for doing it can be materially reduced. Again, it is sometimes found that the sequence of operations is not the best possible and that unnecessary work is being performed for this reason. Another common condition which is discovered at this stage of the analysis is that the part is being shipped about among departments more than is necessary. It may be that, instead of sending a part to a distant department to have a simple operation performed upon it, it would be better to move the work station. 

5. Equipment, Tools, Work Station Design and Setup Analysis .

Item 5.  The equipment or machine analysis starts with the question "Is the machine tool best suited to the performance of the operation of all that are available?" The questions is extended to the question of the option of purchase of a new machine. Would the purchase of a better machine be justified? In the intermediate stage, there may be  existing machines in the company or organization which may be used for more productivity.

The tools used along with the equipment on any operation are  worthy of careful study. Repetitive jobs are usually tooled up efficiently, but there are many opportunities for savings through the use of well-designed tools on small-quantity work which are often overlooked. For example, if a wrench fits a given nut and is strong enough for the work it is to do, usually little further attention is given to it. There are many kinds of wrenches, however. The list includes monkey wrenches, open-end wrenches, self-adjusting wrenches, socket wrenches, ratchet wrenches, and various kinds of power-driven wrenches. The time required to tighten the same nut with each type of wrench is different. The more efficient wrenches cost more, of course, but for each application there is one wrench that can be used with greater over-all economy than any other. Therefore, it pays to study wrench equipment in all classes of work. The same remarks apply to other small tools.

Jigs, fixtures, and other holding devices too often are designed without thought of the motions that will be required to operate them. Unless a job is very active, it may not pay to redesign an inefficient device, but the factors that cause it to be inefficient may be brought to the attention of the tool designer so that future designs will be improved.

The term "setup" is loosely used throughout industry to signify the workplace layout, the adjusted machine tool, or the elemental operations performed to get ready to do the job and to tear down after the job has been done. More exactly, the arrangement of  the material, tools, and supplies that is made preparatory to doing the job may be referred to as the " work-place layout." Any tools, jigs, and fixtures located in a definite position for the purpose of doing a job may be referred to as "being set up'  or as "the setup." The operations that precede and follow the performing of the repetitive elements of the job during which the workplace layout or setup is first made and subsequently cleared away may be called " make-ready" and "put-away" operations.

The workplace layout and the setup, or both, are important because they largely determine the method and motions that must be followed to do the job. If the workplace layout is improperly made, longer motions than should be necessary will be required to get materials and supplies. It is not uncommon to find a layout arranged so that it is necessary for the operator to take a step or two every time he needs material, when a slight and entirely practical rearrangement of the workplace layout would make it possible to reach all material, tools, and supplies from one position. Such obviously energy-wasting layouts are encountered frequently where methods studies have not been made and when encountered serve to emphasize the importance of and the necessity for systematic operation Analysis.

The manner in which the make-ready and put-away operations are performed is worthy of study, particularly if manufacturing quantities are small, necessitating frequent changes in layouts and setups. On many jobs involving only a few pieces, the time required for the make-ready and put-away operations is greater than the time required to do the actual work. The importance of studying carefully these non-repetitive operations is therefore apparent. When it can be arranged, it is often advisable to have certain men perform the make-ready and put-away operations and others do the work. The setup men become skilled at making workplace layouts and setups, just as the other men become skilled at the more repetitive work. In addition, on machine work it is usually possible to supply them with a standard tool kit for use in making setups, thus eliminating many trips to the locker or to the tool room.

6. Material Handling.

Item 6. Material handling is a study in itself. That it has received a great deal of attention on the part of management is evidenced by the wide application of conveyers, cranes, trucks, and other mechanical handling devices. Manual handling, however, is encountered frequently, and should be carefully studied where found. Handling problems are as numerous and varied as the parts handled, but they offer a fertile field for savings. In general, the part that is the least handled is the best handled.

Although it is commonly thought that conveyers can be used to advantage only in mass-production work, there are types on the market that are equally successful in jobbing work. Not only do the latter conveyers eliminate material-handling labor, but if they are used in conjunction with a dispatching system they permit far better production control than is usually obtained in miscellaneous, small-quantity work.

Many plants are laid out, if a careful study has not been made, so that a great deal of unnecessary handling is required, particularly if the plant has gone through a period of rapid expansion. Major changes of layout do not usually result from the analysis of a single job, although they may. However, the matter of general layout should be given at least passing consideration under items 2, 5; and 8 of the analysis sheet. As a result of this preliminary work, the analyst will be in a good position to undertake a major layout revision when the occasion arises.

7. Common possibilities for job improvement.

Item 7. There are a number of changes that can be made to workplace layouts, setups, and methods which are brought to light by job analysis. Of these, there are 10 that are encountered frequently, and 1 or more may be made on nearly every job studied.

1. Install gravity delivery chutes.

2. Use drop delivery.

3. Compare methods if more than one operator is working on
same job.

4. Provide correct chair for operator.

5. Improve jigs or fixtures by providing ejectors, quick-acting
clamps, etc.

6. Use foot-operated mechanisms.

7. Arrange for two-handed operation.

8. Arrange tools or parts within normal working area.

9. Change layout to eliminate backtracking and to permit coupling of machines.

10. Utilize all improvements developed for other jobs.

The possibility of applying them can be recognized without resorting to detailed motion study.


8. Working conditions.

Item 8. Working conditions have an important influence on production. This has been widely recognized during recent years, and the more modern plants usually provide working conditions that the methods engineer considers to be suitable. In the older plants, or in modern plants where methods studies have not been made, poor working conditions are frequently encountered. In most cases, it is best to correct them. It is sometimes difficult to justify the cost of making such improvements by direct labor savings, but there are other factors that must be considered in this connection. The human element cannot be neglected. Conditions that are unhealthy, uncomfortable, or hazardous breed dissatisfaction. Besides lowering production, they increase labor turnover and accidents and often lead to labor unrest.

There are certain other factors that are worthy of at least passing consideration during analysis, and the most important of these are listed as "other conditions" under item 8. The design of the part, of course, plays an important role in the methods that must be used to produce it. In the majority of cases, the design is fixed by the engineering, functional, or appearance requirements of the product, but occasionally a part is encountered that can be redesigned to make its production easier without in any way affecting its ultimate purpose. In addition to this, certain minor features of design can sometimes be suggested that will help to fit the product to the limitations of the tools which are to produce it.

9. Manual Operation (Human Effort)

Item 9. The analysis of the manual method followed in performing the operation is the most important part of the study.

The method that is established after analysis and motion study completes the full operation analysis.



The foregoing gives a general description of the items on the analysis sheet.

The analysis sheet serves as a guide in  collecting information for analyzing an operation in a  process or method.

The analysis check sheet ensures that every issue connected to efficiency improvement relating to each factor is brought into the analysis.

Ohno's Seven Wastes

Overprocessing, Motion  - Defects - Transport -  Waiting - Inventory, Overproduction

You can clearly see Ohno expressed the wastes to be examined in process chart activities. That is why Shigeo Shingo explained Toyota Production System in terms of ASME process chart.

As part of of Operation (Processing: Material Processing), Overprocessing, Motion are to be eliminated. Defects also have to eliminated as part of operation.

As part of Inspection, either inline by the production operator or another operator or inspection the defect occurrences are assessed. Even here, there is the waste of  Overprocessing and  Motion.

As part of Transport Activity evaluation, transport has to be minimized.

As part of investigation of Delays, Waiting times are to be reduced.

As part of evaluation of storage to reduce storage quantity and cost, overproduction and inventory have to be eliminated.

Toyota Production System enriched industrial engineering theory and practice of 1945 to 1950 and gave us enriched industrial engineering.

VSM

IEKC Industrial Engineering ONLINE Course Notes


Learning to See: Value Stream Mapping to Add Value and Eliminate Muda
Mike Rother, John Shook
Lean Enterprise Institute, 01-Jan-2003 - Business & Economics - 102 pages

In 1998 John teamed with Mike Rother of the University of Michigan to write down Toyota's mapping methodology for the first time in Learning to See. This simple tool makes it possible for you to see through the clutter of a complex plant. You'll soon be able to identify all of the processing steps along the path from raw materials to finished goods for each product and all of the information flows going back from the customer through the plant and upstream to suppliers. With this knowledge in hand it is much easier to envision a "future state" for each product family in which wasteful actions are eliminated and production can be pulled smoothly ahead by the customer.

Much more important, these simple maps - often drawn on scrap paper - showed where steps could be eliminated, flows smoothed, and pull systems introduced in order to create a truly lean value stream for each product family.


In plain language and with detailed drawings, this workbook explains everything you will need to know to create accurate current-state and future- state maps for each of your product families and then to turn the current state into the future state rapidly and sustainably.

In Learning to See 2003 edition you will find:

A foreword by Jim Womack and Dan Jones explaining the need for this tool.
An introduction by Mike Rother and John Shook describing how they discovered the mapping tool in their study of Toyota.
Guidance on identifying your product families.
A detailed explanation of how to draw a current-state map.
A practice case permitting you to draw a current-state map on your own, with feedback from Mike and John in the appendix on how you did.
A detailed explanation of how to draw a future-state map.
A second practice case permitting you to draw a future-state map, with "the answer" provided in the appendix.
Guidance on how to designate a manager for each value stream.
Advice on breaking implementation into easy steps.
An explanation of how to use the yearly value stream plan to guide each product family through successive future states.
More than 50,000 copies of Learning to See have been sold in the past two years. Readers from across the world report that value stream mapping has been an invaluable tool to start their lean transformation and to make the best use of kaizen events.
http://books.google.co.in/books/about/Learning_to_See.html?id=mrNIH6Oo87wC



What are the origin's of Value Steam Mapping?

Baudin' Explanation  - http://michelbaudin.com/2013/10/25/where-do-value-stream-maps-come-from/

Origin in Toyota’s Operations Management Consulting Division (OMCD)

Materials and Information Flow diagram was developed at Toyota’s Operations Management Consulting Division (OMCD), for selective use with suppliers — that is, wherever the main issue is with flows of materials and information related to these flows.

The OMCD, whose Japanese name actually means “Production Investigation Division” (生産調査部). is a group of 55 to 65 high-level TPS experts.

The technique was brought to the US by the Toyota Supplier Support Center (TSSC).

According to John Shook, Materials and Information flow diagrams were created by Toyota’s OMCD group. They were introduced to the U.S. by TSSC,

Jim Womack and Dan Jones introduced the concept of “value stream” and in Lean Thinking told readers to map them. While the book had an example and descriptions, the process wasn’t laid out. At that time, Mike Rother had just become very interested in Toyota’s M&I flow mapping so John introduced him to Jim  Womack and Dan Jones.

Mike was the lead author (John Shook is co-author) of the workbook Learning to See and developed the mapping workshop. Dan Jones came up with the title Learning to See. Jim Womack and Dan Jones coined the term “value stream” and “value-stream mapping.”

John Shook said it was and still is used by the select group of TPS experts, mostly in the OMCD organization. (I think it is now Operations Management and Development Division.) So, the tool came to LEI in a roundabout way from TSSC.



 ”John (Shook), has known about the “tool” for over ten years, but never thought of it as important in its own right.  It is used by Toyota Production System practitioners to depict current and future, or “ideal” states in the process of developing implementation plans to install lean systems. At Toyota, while the phrase ‘value stream’ is rarely heard, infinite attention is given to establishing flow, eliminating waste, and adding value.”


Materials and Information Flow Analysis at TSSC
TSSC still teaches Materials and Information Flow analysis.
http://www.tssc.com/kaizenleader1.asp#Material_&_Information_Flow:

“Material & Information Flow: day in classroom designed to develop the skill to document the current condition and locate the process bottleneck. 1 day shop floor focused on grasping the current condition and finding the bottleneck in an actual shop floor setting.Length: 1.5 days”





Microlevel versus Macro Level

Ohba says that one should start at the micro level — machines, cells, workstations, tooling, fixtures, operator job design, etc. — not at the macro level — lines, departments, suppliers, customers, etc. His reasoning is that you need to develop skills before you can address macro level issues. And he is saying that you should not start with VSM because it is a macro level tool. What Ohno does not say in his presentation is how you find out where in the plant you should start at the micro level. To me, an appropriate pilot project must meet the following conditions:

It must provide an opportunity for tangible, short-term performance improvements.
Both management and the work force in charge of the target process must be willing and able.
The target process must have at least one more year of economic life.
To identify such opportunities, you need to observe operations directly, interact with operators, managers and engineers, and analyze data. VSM is one of the tools that are useful in doing this, but it is not the only one, and it is not always needed.

One week of process kaizen and one week of system kaizen. During that week we used MIFD. Later on they started using it more and more in the plants only when needed.”

 The “Value Stream Mapping” Label

“Materials and Information Flow” accurately describes what the technique is about, and is almost self-explanatory.

According to  Gary Stewart, a 23-years Toyota veteran:

“The VSM process was known internally simply as “process mapping” – (or occasionally later as MIFD – but that was more specific to OMCD ) – it is only one of a suite of tools that should be used together to understand the process from high level to great detail. I think today the term VSM and the use by consultants of the term VSM is  more of creating a branding difference in both Marketing and Consulting. In Marketing “process mapping” does not sound very sexy – But with Value Stream Mapping – you have a major brand differentiator.

Unquestionably, Jim Womack is an outstanding marketer. “Process Mapping,” “Materials and Information Flow Analysis,” are all terms that, at best, appeal to engineers. Any phrase with “value” in it, on the other hand, resonates with executives and MBAs.



Art Smalley’s perspective on VSM


“Value stream mapping, for instance, is perhaps the most widely used tool in lean programs today.



A third dimension, human motion, is often added to the mix for consideration as well at Toyota. As TPS evolved internally and was rolled out to supplier companies externally a consistent problem was insufficient investigation into the details of material flow, information flow, and human motion in the process. It became a requirement for engineers and others in charge of manufacturing processes and line conversion work at suppliers to make maps.

The emphasis was to draw both detailed standardized work charts depicting operator motion, and flow charts depicting material storage locations, scheduling points, and operator work sequence before the start of production. In other cases, this tool was used externally to find ways to convert lines to more efficient ones.

The key point is that the tool was created to analyze and solve a specific category of problems Toyota faced in new production lines and in helping suppliers implement lean. From this fairly specific local origin in Toyota, the tool was slightly modified (the human motion emphasis was reduced) and popularized in the U.S. by my good friend and former Toyota colleague John Shook, and his co-author Mike Rother, in their insightful, best selling workbook “Learning to See”.

The book is about learning to see what is primarily a material and information flow problem, or essentially elements of the JIT pillar of Toyota’s production system (flow, takt time, level, and pull production).

By design it doesn’t even attempt to address the topic of Jidoka for example which Toyota considers an equally if not more important support pillar than JIT or equipment stability. The technique used in the workbook simply measures the overall manufacturing lead-time versus production value add time. Everything non-value adding (i.e. the waste) is to be eliminated and answering seven specific questions outlined in the workbook will help you accomplish some of this goal.

Overall, however, when the 4M’s of manufacturing (man, machine, material, and method) are considered you’ll realize that this tool mainly considers the material (and information) flow component. The other 3M’s are much less emphasized and one other important M – metrics – is expressed chiefly in terms of lead-time and value-add time.

This is fine for Toyota. Internally they well know the limits of the tool and understood that the it was never intended as the best way to see and analyze every waste or every problem related to quality, downtime, personnel development, cross training related issues, capacity bottlenecks, or anything to do with profits, safety, metrics or morale, etc.

No one tool can do all of that. For surfacing these issues other tools are much more widely and effectively used. Unfortunately, the average user of the workbook tends to copy the pattern expressed in value stream mapping regardless of the nature of their manufacturing problems.

The unintended consequence of the success of the method has been to convince many people that it is a universal tool for identifying all problems in manufacturing operations.

This guidance however biases companies with major quality, downtime, or factor productivity problems to deemphasize them since those items are not surfaced well using the method and questions outlined in value stream mapping. The tool just does not frame these problems well by design. Couple this effect with the fact that most lean efforts already have a disproportionate bias towards the concept of “flow”, and there is a recipe for inherent danger.

For example instead of learning to see what is truly broken in their processes companies wind up typically focusing on a particular subset of operational problems chiefly that of flow and lead-time related issues.”

John Shook in VSM Misunderstandings - http://www.lean.org/library/shook_on_vsm_misunderstandings.pdf

Seeing the Whole Value Stream, 2nd Ed.

Jim Womack, Dan Jones

Lean Enterprise Institute, 2011 - Business & Economics - 108 pages

When the first edition of Seeing the Whole was published in 2003, the world was in a mad rush to outsource and offshore in pursuit of suppliers with drastically lower piece prices. Today the situation is very different; currencies have shifted, labor costs in many low-wage countries have risen, and the potential for squeezing further price reductions from suppliers is largely exhausted. What’s more, high product quality and rapid response to changing customer demands have proved elusive along unwieldy, opaque supply chains. 

Seeing the Whole Value Stream provides managers with a proven method for understanding and improving the value-creating process that suppliers share with customers. By identifying all the steps and time required to move a typical product from raw materials to finished goods, the authors show that nearly 90 percent of the actions and 99.9 percent of the time required for the supply chain's current state create no value. In addition, the method clearly shows demand amplification of orders as they travel up the supply chain, steadily growing quality problems, and steadily deteriorating shipping performance at every point up stream from the customer.

Applying the method to a realistic example, the authors show how four firms sharing a value stream can create a win-win-win-win future in which everyone, including the end consumer, can be better off.

The workbook goes step-by-step through an improvement process that converts the traditional supply chain of isolated, compartmentalized operations into an ideal future-state value stream in which value flows from raw materials to customer in just 6 percent of the time previously needed. The dramatically improved value stream also eliminates unnecessary transport links, inventories, and handoffs, the key drivers of hidden connectivity costs.

The information in the 108-page book is supported by multiple diagrams, charts, and maps. The main sections of the book are:

Getting Started

The Current-State Map

The Extended Value Stream

Future States 1 & 2

Ideal State

Perspectives on Extended Value Streams: 5 essays

In response to feedback asking for examples in other sectors and questions about how to understand supply chain costs more accurately, five essays have been added to the book for this new edition. These essays demonstrate how real companies have taken on the challenge of improving their extended value streams working in collaboration with their suppliers and customers.

The new essays for the book are:

Spreading value-stream thinking from manufacturers to final customers through service providers—extending the wiper example. This extends the value-stream analysis in the first edition—using the same example of a windshield wiper—through the auto service system to the end customer.

Applying extended value-stream thinking to retail—a look at the Tesco story. This follows the path of an individual product through a complex retail channel from manufacturer to end customer.

Learning to use value-stream thinking collaboratively with suppliers and customers. This essay demonstrates how a second-tier supplier convinced much larger partners to embrace collaborative thinking about their shared value stream.

Product costing in value-stream analysis. An essay on adding realistic costing to value streams to more accurately understand total cost.

Seeing and configuring the global value stream. This essays shows how a manufacturer can analyze all of the value streams in a complex supply network.

Preview the book: https://books.google.co.in/books?id=llLhQ93jKyYC

Seeing the Whole Value Stream

https://www.slideshare.net/LeanUK/seeing-the-whole-value-stream

Lean and the Extended Value Stream

How does lean manufacturing apply to the entire supply chain? This presentation talks about the application of lean to the entire value stream. Presentation by EMS Consulting Group, Inc. www.emsstrategies.com

https://www.slideshare.net/darrendolce/lean-and-the-extended-value-stream?next_slideshow=1

Applications

8 SIMPLE STEPS TO IMPLEMENT VALUE STREAM MAPPING (VSM)

OLANAB CONSULTS

https://www.olanabconsults.com/articles/8-simple-steps-to-implement-value-stream-mapping-vsm

Shahrukh Irani

https://ie.binus.ac.id/2021/04/30/enhancing-value-stream-mapping-for-manufacturing/

Enhancing Value Stream Mapping for Manufacturing, ISE Magazine April 2021 Volume: 53 Number: 4

By Shahrukh A. Irani

Using Value Stream Mapping to Improve Forging Process - M.Sc. thesis (MIT)

http://alvarestech.com/temp/capp/AppleFoxconnEstrategiaManufaturaValueStreamMapsProcessMaps/%5BArticle%5D%20Using%20Value%20Stream%20Mapping%20(VSM)%20to%20Improve%20Forging%20Processes_By%20Stephen%20G.%20King_2004_(Scan).pdf

2013 - Karen Martin - Value Stream Mapping - One Hour Video Presentation

She wrote a book on VSM

_______________

https://www.youtube.com/watch?v=5YJYMLaV9Uw

_______________

The seven value stream mapping tools

Peter Hines and Nick Rich

Lean Enterprise Research Centre, Cardiff Business School, Cardiff, UK

International Journal of Operations & Production Management, Vol. 17, No. 1, 1997, pp. 46-64. 

The value stream is a far more focused and contingent view of the value-adding process.

Seven Value Stream Mapping Tools

Process activity mapping
Supply chain response matrix
Production variety funnel
Quality filter mapping
Demand amplification mapping
Decision point analysis
Physical structure

Mapping tool                                          Origin of mapping tool

(1) Process activity mapping                  Industrial engineering

(2) Supply chain response matrix           Time compression/logistics

(3) Production variety funnel                 Operations management

(4) Quality filter mapping                      New tool

(5) Demand amplification mapping       Systems dynamics

(6) Decision point analysis                    Efficient consumer response/logistics

(7) Physical structure mapping              New tool

What is the objective? The objective is to develop a lean value stream. Let characterize the present value steam as fat value stream.


Paper by Prof Shahrukh A Irani

Value Stream Mapping enhanced with Industrial Engineering Tools

Sadono C. Djumin, Yuri Wibowo and Shahrukh A. Irani
Department of Industrial, Welding and Systems Engineering
The Ohio State University
Columbus Ohio 43210

http://iwse.eng.ohio-state.edu/ISEFaculty/irani/Industrial%20Engineering%20Studies/Value%20Stream%20Mapping%20from%20an%20Industrial%20Engineering%20Viewpoint.htm

Ud16.10.2021

Pub 20.6.2012

Blog articles on VSM

Value Stream Mapping to Highlight Inventory (Blocks to material flow) - Origins - Evolution and Applications

Value Stream Mapping, Process Mapping and Process Flow Charts

The Seven Value Stream Mapping Tools - Peter Hines and Nick Rich - Paper

Learning to See: Inventories (Delays) Between Processes - Value Stream Mapping - Rother and Shook - Book Information

Value Stream Mapping - The Concept