Operation process charts records the core engineering activities in engineering processes. Improvement of engineering processes, engineering operations, and engineering elements is the core activity of industrial engineering. Industrial engineering is focused on cost reduction of products and processes through productivity improvement of engineering resources used in the processes.
Operation process chart must first be drawn for each engineering process and improved first by industrial engineers. Then the flow process chart showing transport, delays and longer storage are to be drawn in the flow process chart and in the flow process chart analysis, the focus can be the flow.
An operation process chart is a graphic representation of the points at which materials are introduced into the process, and of the sequence of material processing and inspections. Material handling activities, especially between machines, work stations and inspection benches are not included in it.
It can have any information considered desirable for analysis, such as time required and location.
PRINCIPLES AND PRACTICES FOR CONSTRUCTION OF OPERATION PROCESS CHARTS - ASME Standard, 21 May 1947.
Operation process charts are drawn on plain paper of sufficient size to accommodate the chart.
Identification Information on the Chart
The operation process chart should be identified by a title placed at the top of the chart. In the case of chart is to be folded for filing, the identification information should also be placed in such a position on the folded chart that it is visible for identification of the required chart.
At the top the words "Operation Process Chart" are written first. The identifying information which is always necessary is as follows:
Process of the part or assembly charted
Specify Present Method or Proposed Method
Drawing number, part number, or other identifying number of the part or the assembly
Date Charted
Charted by
Additional information which will be useful includes:
Location: Plant/Building/Department
Chart Number
Sheet No. of Sheets
Approved by
Major Conventions
The sequence in which the events depicted on the chart must be performed is represented by the arrangement of process chart symbols on vertical flow lines. Material, either purchased and directly used or upon which work is performed during the process, is shown by horizontal flow lines.
One of the parts going to make up the completed product is selected for charting first. Usually a chart of the most pleasing appearance will be obtained by choosing the component on which the greatest number of operations is performed. If the chart is to be used as a basis for laying out a progressive assembly line, the part having the greatest bulk to which the smaller parts are assembled would be chosen.
20 When the component which is to be charted first has been chosen, a horizontal material line is drawn in the upper right hand portion of the chart. A description of the material is recorded directly above this line. The description may be as complete as is deemed necessary. Usually a brief description, such as "20 ga. Steel Sheet" or "'/« in. Hex. Brass Bar" will suffice, since it is the purpose of the chart to give a picture of the process as a whole rather than the detailed specifications of the materials used. In order to identify the part itself, the name and identifying number are recorded in capital letters directly above the material description. (The details of the materials as well as various steps in the process are to be documented separately for detailed investigation.)
21 A vertical flow line is next drawn down from the right hand end of the horizontal material line. Approximately V* in. from the intersection of the horizontal material line and the vertical flow line, the symbol is drawn for the first operation or inspection which is performed. To the right of this symbol, a brief description of the event is recorded, such as "Bore, chamfer, and cut off" or "Inspect material for defects."
To the left of the symbol is recorded the time allowed for performing the required work (The time taken to perform the work during the observation also needs to be recorded!.). [Work measurement literature has not discussed this issue appropriately]
Other pertinent information which it is considered will add to the value of the chart, such as department in which the work is performed, male or female operator, cost center, machine number, or labor classification, is recorded to the right of the symbol below the description of the event.
22 This charting procedure is continued until another component joins the first. Then a material line is drawn to show the point at which the second component enters the process. If it is purchased material, a brief identification of the material, such as "Wing Nut No. 18023" or "X and Y Co. No. 80 Filter" is placed directly above the material line. If work has previously been done line is erected from the left hand end of the material line. The material from which the component was made and the operations and inspections performed on it are then charted following the conventions described above. This same procedure is repeated as each new component joins one which is being charted. As each component joins the one shown on a vertical flow line to its right, the charting of the events which occur to the combined com-[>onents is continued along the vertical flow line to the right. The final event which occurs to the completed apparatus will thus appear in the lower right hand portion of the chart.
23 Operations are numbered serially for identification and reference purposes in the order in which they are charted. The first operation is numbered 0-1, the second 0-2, and so on. When another component on
which work has previously been done joins the process, the operations performed upon it are numbered in the same series. They will be identified as 0-1, 0-2, 0-3, and 0-4. If a second component then joins the first, the first operation performed on the second component will be identified as 0-5. If two more operations are performed on the second component before it joins the first, they will be numbered 0-6 and 0-7. The first operation performed after the two components have come together would then be identified as 0-8. (This gives convention when the whole finished (assembled) product is charted).
22 This charting procedure is continued until another component joins the first. Then a material line is drawn to show the point at which the second component enters the process. If it is purchased material, a brief identification of the material, such as "Wing Nut No. 18023" or "X and Y Co. No. 80 Filter" is placed directly above the material line. If work has previously been done line is erected from the left hand end of the material line. The material from which the component was made and the operations and inspections performed on it are then charted following the conventions described above. This same procedure is repeated as each new component joins one which is being charted. As each component joins the one shown on a vertical flow line to its right, the charting of the events which occur to the combined com-[>onents is continued along the vertical flow line to the right. The final event which occurs to the completed apparatus will thus appear in the lower right hand portion of the chart.
23 Operations are numbered serially for identification and reference purposes in the order in which they are charted. The first operation is numbered 0-1, the second 0-2, and so on. When another component on
which work has previously been done joins the process, the operations performed upon it are numbered in the same series. They will be identified as 0-1, 0-2, 0-3, and 0-4. If a second component then joins the first, the first operation performed on the second component will be identified as 0-5. If two more operations are performed on the second component before it joins the first, they will be numbered 0-6 and 0-7. The first operation performed after the two components have come together would then be identified as 0-8. (This gives convention when the whole finished (assembled) product is charted).
24 An operation number once used is never repeated on the same chart. If after a chart has been completed, it becomes necessary to add an operation to the process be tween two operations, it is permissible to identify the new operation with the number of the preceding operation followed by the
subscript "a." Thus an operation inserted between 0-4 and 0-5 would be identified as 0-4a.
25 Inspections are numbered in the same manner in a series of their own. They are identified as INS-I, INS-2, and so on.
OTHER CONVENTIONS
30 It sometimes happens that a part may follow two or more alternate courses during part of the process. For example, a partially processed part may be inspected at a certain point. If it is satisfactory in every respect, it may go directly to the assembly. If not, it may require one or more corrective operations, depending upon the nature of the defects.
31 When it is desired to portray a condition of this kind on an operation process chart, a horizontal line is drawn below the being at the intersection of the vertical flow line and the horizontal line. Vertical flow lines are then dropped from the horizontal line for each alternative which it is desired to show. If no operations or inspections are performed during one alternative, a vertical flow line only is shown. In all cases, operation and inspection symbols are added in the conventional manner. They are numbered
serially beginning with the first unused number in the operation or inspection series. The symbols on the flow line furthest to the left are numbered first, then those on the next flow line to the right, and so on until all have been numbered.
32 When all of the alternative paths have been charted, a horizontal line is drawn connecting the lower ends of all of the alternate flow lines. From the mid-point of this line, a vertical flow line is dropped and the balance of the process is charted in the conventional manner.
33 In some cases, it will be found that the same component is used at two or more different points in the same process. If it is a purchased part, it may be shown in the conventional manner each time it enters the process. If it is a part upon which work has previously been done, however, it will add to
chart if the component is completely charted every time it enters the process, particularly if its own processing is extensive. To avoid unnecessary charting work, the second time a part is shown entering a process, it is represented by a horizontal material line above which is written the name of the part and a
reference to the operation numbers which show the processing it has undergone as "Hand wheel No. 851A, See 0-6 to 0-12 incl."
34 In general, an operation process chart should be so constructed that vertical flow lines and horizontal material lines do not cross. On charts of complicated processes, this is sometimes difficult to avoid. When it is necessary to cross a vertical flow line and a horizontal material line, a curved line is used at the crossing to show that no junction occurs there.
35 In some cases, the unit shown by the chart changes as the process progresses. The chart might start out showing the operations performed on a long bar. The bar might subsequently cut into short lengths so that the operations performed thereafter would apply to the short pieces rather than the long bar.
Whenever it is desired to show the unit which is being charted, it is the convention to break the vertical flow line by drawing two parallel horizontal lines about l1/* in- long and '/< in. apart centered with respect to the vertical flow line. Between these lines the unit which is to be followed during the subsequent operations and inspections is shown.
SUMMARY
36 When a proposed method is to be presented by an operation process chart, it is often desirable to show the advantages which it offers over the present method. This may be done by including with the information shown on the chart a summary of the important differences between the two methods.
37 This summary may take the form as given at the bottom of this page.
38 The summary should be placed in a prominent location on the chart. On a small 8Vs in. X 11 in. chart, it will usually be in the lower left hand corner. In the case of a folded chart, it will be on the outside when the chart is folded. It may also be desirable to show it on the inside
Disassembly
26 The conventions followed for portraying disassembly operations are quite similar to those used for assemblies. Material is represented as flowing from the process by a horizontal material line drawn to the right from the vertical flow line approximately 'A in. below the symbol for the disassembly operation. The name of the disassembled component is shown directly above the horizontal material line. The subsequent operations which are performed on the disassembled component, if any, are shown on a vertical flow line extending down from the right-hand end of the horizontal material line.
27 If the disassembled component is later reassembled to the part or assembly from which it was disassembled, that part or assembly is shown as feeding into the now line of the component. This practice moves the major vertical flow line always to the right. Thus, when disassembly operations are to be shown, the chart cannot be started in the upper right hand corner of the form, but must be started further to the left.
28 In numbering the operations, it is the practice to number the operations performed on the disassembled component after disassembly before numbering the operations on the part from which it was disassembled. Then if the part later rejoins the disassembled component, the conventional numbering practices may be followed. This practice also applies to inspections.
CONCLUSION
39 It is recognized that the above description of principles and practices for construction of operation process charts may not cover every conceivable situation which it may be desired to show. Probably at least 95 per cent of the situations which are ordinarily encountered in industry are covered, however. The balance may be charted satisfactorily by following the prescribed conventions as closely as possible, representing the unusual situations with the objective of clearness uppermost in mind. A process chart is a means to an end rather than an end in itself. If it performs its function and is reasonably clear to all who study it, it may be considered to be a satisfactory chart.
ASME (1947) Report Hathitrust Website page
https://babel.hathitrust.org/cgi/pt?id=mdp.39015039876274&view=1up&seq=6
Work Measurement for Recording Times in Process Charts is ignored in current work measurement literature.
Current work measurement is focused on measuring time for fixing standard time for the whole task. Even though element breakup of the task is discussed it is still to facilitate standard time determination for the whole task. Even the standard data chapter does not emphasize compulsory development of standard data for all common elements in the firm.
Analysis of the Operation Chart
Operation Analysis described by Maynard and Stegemerten is the detailed procedures to be applied to each processing operation (O) and inspection operation (INS). The work of the machine and the work of the man has to be recorded in detailed. For machine work operation analysis sheet or operation information sheet described by Maynard and Stegemerten can be used. For the analysis of Man Work, the Two handed process chart is the appropriate chart.
Information from DFMA materials has application in Operation Process Chart Analysis.
Engineering in Industrial Engineering - Machine work study or machine effort improvement, value engineering and design for manufacturing and assembly are major engineering based IE methods. All are available as existing methods.
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https://nptel.ac.in/content/storage2/courses/107103012/module2/lec1.pdf
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https://nptel.ac.in/content/storage2/courses/107103012/module2/lec3.pdf
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Powder Metallury
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Module 3 - Machining
Machining
Machining - General
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Turning
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Round Holes
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Milling
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Shaping, Planing and Slotting
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Broaching
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Module 4 - Forming
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https://nptel.ac.in/content/storage2/courses/107103012/module4/lec2.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module4/lec3.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module4/lec4.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module4/lec5.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module4/lec6.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module4/lec7.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module4/lec8.pdf
Module 5
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DESIGN FOR POLISHING AND PLATING
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https://nptel.ac.in/content/storage2/courses/107103012/module5/lec3.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module5/lec4.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module5/lec5.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module5/lec6.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module5/lec7.pdf
Module 6
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https://nptel.ac.in/content/storage2/courses/107103012/module6/lec2.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module6/lec3.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module6/lec4.pdf
Module 7
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https://nptel.ac.in/content/storage2/courses/107103012/module7/lec2.pdf
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Module 8
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https://nptel.ac.in/content/storage2/courses/107103012/module8/lec2.pdf
https://nptel.ac.in/content/storage2/courses/107103012/module8/lec3.pdf
You can access files from the FaceBook Group
Management and Industrial Engineering - Effectiveness and Efficiency
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Time Comparisons and Improvements: Allowed time is indicated in the charts and also the time being actually taken. Hence it is a point of further evaluation. Also based on benchmarking, best outside performance can be ascertained and then the operation can be evaluated for improvement.
New engineering developments
Mechanization and Automation Possibilities
UD. 27.12.2021
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