Sunday, August 15, 2021

Method Study - Ralph M. Barnes - Important Points of Various Chapters






Book: Motion and Time Study: Design and Measurement of Work, Ralph M. Barnes





Ralph Barnes and H.B. Maynard are contemporaries and both have synthesized the existing industrial engineering literature of the period 1930 to 1940 in the books published by them. Both have indicated the full scope of industrial engineering (machine effort, human effort). Barnes focused on detailed study and improvement of operator method. He discussed equipment related issues relevant for the manipulation by the operator only.

This point needs to be emphasized again that industrial engineering has to primarily examine and improve engineering elements of engineering systems to increase productivity (example - collect for corochuck). Engineering is the provision of engines to provide additional power and advantage to persons. Operators run the equipment and tools used in engineering systems and therefore industrial engineers focus on improvement of human effort also to assure productivity of the system. Industrial engineering is better explained as engineering-system efficiency (productivity)   engineering and human effort efficiency (productivity) engineering.

Chapter 1. Productivity

Productivity Definitions

The ratio of output to some or all of the resources used to produce the output.

Labor productivity
Capital productivity
Material productivity

Barnes has indicated that productivity of three important resources used in production or engineering systems is important. Labor, capital and material are the three important resources. For increasing the productivity of labor, motion and time study are used. It is important to specifically highlight that Barnes' book is on "Motion and Time Study" only. It does not cover full industrial engineering. But Barnes clearly stated the importance of capital productivity that is machine productivity and material productivity. Cycle time reduction that reduces inventory in the system fall in the area of material productivity or more appropriately as material flow productivity. 

Productivity Index

Calculated by US Bureau of Labor Statistics for the entire economy as well as parts of the economy

An input-output model of the firm is given in  Figure 1.

Eli Lilly has century long record of productivity improvement

Technological innovation

Productivity increases by technological innovations - Example Dial telephone, farm machinery, computers.

Examples Texas instruments and Hewlett Packard were also given.

Measurement of Individual Worker Productivity

Standard Time

Actual output * Standard time per unit/Hours of effort  = productivity index

Motion and Time Study for Increasing Labor Productivity



Chapter 2  Definition and Scope of Motion and Time Study


Some have suggested that the term methods engineering, work design, work study, or job design should be used in place of motion and time study, and it may be that eventually these terms will come into wider use. There is however, at the present time a trend toward making work methods design synonymous with motion study and work measurement synonymous with time study. Therefore motion and time study and work methods design and work measurement will be used interchangeably in this book.

Motion Study or Work Methods Design (Barnes equates Motion Study to Work methods design)

1. Developing the Preferred Method.
2. Standardizing the Operation - Written Standard Practice
3. Determining the Time Standard - Work Measurement
4. Training the Operator


3 Patterns in which Motion and Time Study is used

A.  By industrial engineers - staff specialists - Originated in 1880s - Taylor and Gilbreth advocated involving operators and taking their feedback after they use the new method.
B.  Also used by Managers and Line Supervisors -Introduced in 1930s (Alan Mogensen - Work simplification workshops)
C. Also used by workers themselves in teams or groups - Came into use in 1950s


Chapter 3. History of Motion and Time Study


Taylor's Use of Time Study

Time study was initially started by F.W. Taylor in 1881 in the machine shop of the Midvale Steel Company. (Detailed note by F.W. Taylor).

Taylor was a pioneer in applying the systematic approach to that phase of industry which intimately affects the worker. He understood that he was dealing with a human problem as well as with materials and machines, and he approached the human side of his investigations with an understanding of its psychological aspects.

Human Effort Industrial Engineering - 


Barnes wrote, "So great has been Taylor's contribution to the whole problem of effective utilization of human effort in industry that we can profit from a review of some of his work in this field."



Taylor's Principles of Management

Taylor's Investigation of Shoveling

Taylor found that shovelers were lifting loads of 3.5 pounds when handling rice coal and up to 38 pounds to the shovel when moving ore. Taylor's experiments showed that with a load of 21.5 pounds on the shovel, a man could handle a maximum tonnage of material in a day.

The Beginning of Motion Study

In 1885, Gilbreth, as a young man of seventeen, entered the employ of a building contractor. Gilbreth observed that brick layers were using different set of motions and some set of motions were more productive. Gilbreth developed interest in developing more productive motion sets and methods in bricklaying.  He invented a scaffold which could quickly and easily raised as the wall height is increasing due to construction. The scaffold on which the bricklayer is standing has a bench for holding the bricks and mortar at convenient height. The bricks were placed in an orderly manner by a helper. With such improvements, the motions to be made by a bricklayer were reduced to 4.5 from the earlier 18, The average bricks laid increased to 350 per man per hour from the old rate of 120 bricks  per man per hour.

Industrial Engineering is System Efficiency Engineering and Human Effort Engineering. - Narayana Rao


Chapter 4. General Problem Solving Process


1. Problem Definition

Example: A farm plants peas in 7000 acres each year from early March to the the first of April. Harvesting is a problem and  the harvesting crew works round the clock and still cannot harvest all the acres. Dr. C.W. Thornthwaite, climatologist for the farm attacked the problem from planting side. He scheduled planting in such a way that a definite number of acres are ready for harvesting every day during the harvesting season and hence there was no confusion and overload on the harvesting team. The problem could have been tackled from the side of harvesting also. But this solution is more ideal according to the author.

2. Analysis of the Problem

The author highlights that some time certain restrictions are told by the persons who are using the current process. They need to be examined carefully. He gives the example of citrus fruit packing. They were packed in wooden crates wrapped in tissue paper with the assumption that they need ventilation. But now they are packed in cardboard cartons without any ventilation. Hence the earlier assumption was not correct.

3. Search for Possible Solutions
Study of texts, handbooks, magazines, technical brochures of various companies, search of relevant websites.

The author gives two examples of new technology to support the idea that search for possible solution should extent to new technologies.

Examples one is an electronic thermometer. The thermometer has a probe onto which a disposable probe is placed and inserted under the patient's tongue. In the 15 to 25 second, the digital reading will come. As a disposable probe is used, there is no possibility of infection spreading to other patients and also the thermometer need not be sterilized. There is no danger of patients biting the thermometer also.

Second example is related to special polypropelene foam material developed by Dupont.

Creative thinking by individuals and groups to be employed.


4. Evaluation of Alternatives

Role of Engineering Economics in Evaluation of Alternatives

In certain types of problems, evaluation would center around the total capital that would be invested in each of the several proposed methods, expected life of the equipment, scrap value and annual operating cost. From these economic or cost figures, the rate of return on the investment per year is calculated.  Direct labor required for each of the proposals need to be worked out. Predetermined motion time systems (MTM) could be used for this purpose. But to visualize the motions to be made by the operators, mock-ups of jigs and fixture may have to be made. Some companies have special laboratories and workshops for such projects.


5. Recommendation for Action

Chapter 5. Work Methods Design - The Broad View


The over-all process of putting a new product into production

1. Planning
2. Pre-production
3. Production

Planning

Six basic planning functions

1. Design of the product
2. Design of process
3. Design of Operator work method
4. Design of  tools, jigs and fixture
5. Design of plant layout
6. Determination of standard time

Preproduction

Resources are acquired and installed and trial runs are made.

Production

The production system is producing as per market requirement or demand.

Two attention areas of Method study person.

1. Preventing the method from deteriorating or deviating adversely from the planned methods,
2. Constantly being on the look out for improvement options, and when one is found, putting it into effect. Also the methods have to be periodically subjected to methods improvement study.

An ongoing manufacturing process provides opportunities to improve and redesign operator methods, to eliminate manual tasks, and make the job easier for the worker. New equipment and tools make existing facilities obsolete and provide cost reduction opportunities. New and better materials are developed or become available providing scope for changes in product parts design.

Example given - Elizabeth Arden Inc. lipstick manufacturing process

In the zeroth year or the starting of the study, the units produced per labor hour was 76. By end of 7 years, the productivity increased and the unit produced per labor hour was 179.

Chapter 6. Work Methods Design - Developing A Better Method


Approach for developing the preferred method

1. Eliminate all unnecessary work.
2. Combine operations or elements.
3. Change the sequence of operations
4. Simplify the necessary operation (Operation analysis)


2. Combine operations or elements.
Example given: In a furniture factory, an operator unloaded wooden logs from a truck and loaded them into a molding machine. On the other end, another operator took the moulded item and loaded it into a another truck. In the redesign, another short conveyer brought back the moulded item to the operator who was loading the machine. The truck was partitioned into four comparments and only three were loaded. In the empty compartment the moulded pieces were loaded by the same operator. Thus the operation was completed by only one operator and also the need for another full truck was eliminated,

3. Change the sequence of operations

In one plant small assemblies were made and stored in a stock room. Inspection was done subsequently. This was resulting in certain problems and in the rearrangement inspection was done immediately after the assembly and then only the finished goods were kept in stock for despatch.

4. Simplify the Necessary Operations - Improve the Necessary Operations

After improving the process using three steps of eliminating the operation, combining operations or elements (or even breaking them further), and changing the sequence of operations, the operation itself can be studied in detail to simplify or improve it.  Study of process is the study of overall picture and then smaller details of each step of the process can be attempted.

One of the best ways to do methods improvement is to question every thing about the method. The design of the product itself can be questioned and investigated (product industrial engineering). The equipment and tools are to be investigated and improved. The materials used are to be examined. The working conditions are to be evaluated. The operator method has to be studied and improved.


Barnes was quiet clear that his text is concerned basically with the description of design and improvement of operator work method and measurement of time required to do it.  That is why he has given the following questions as important in investigating the method (operator method).

1. What is done? At this stage of operation analysis, the analyst must first clearly define what is being done.

2. Who does the work? It is directed at the person who is given the work. The further questions are Why this person? Can any body else do it better? Can a less skilled person do this work if some changes can be done?

3. Where is the work done? 

4. When is the work done?

5. How is the work done? Why is it done this way? What are alternatives?  This step requires application of principles of motion economy and careful analysis.




Chapter 7. Process Analysis


Process Chart

Gilbreth Symbols
ASME symbols

Flow Diagrm

Gang Process Chart

Example: Installation of a Pipe Bridge in Procter and Gamble Company

The earlier procedure was to pick up the the bridge with a crane and fasten it in place and then install pipe and conduit in the bridge at a height. The procedure was changed to installing pipe and conduit while the bridge is on the ground and then lifting it to the required height and fastening it.

Chapter 9. Operation Analysis

Full details of Operations Analysis - Book by Maynard and Stegemerten

It is important to the note "Operation Analysis" is a method used by Westinghouse. It is described in detail in a book by Maynard. Barnes included the description of operation analysis in a chapter.

Because Barnes' focus in on operator method, he discusses in detail the operation chart or the left- and right- hand chart.

Operation Chart or the left- and right-hand chart.

Bolt and Washer assembly example


Check Sheet for Operation Analysis was given only briefly.
1. Machine
    A. Setup
    B. Operation
2. Materials
3. Materials Handling - Plant Layout
4. Tools, Jigs and Fixtures
5. Operator
6. Working Conditions


Example: Spraying inside and outside of metal box cover.

Initially one side is painted and the cover is put in an oven and then the other side is painted.

A device was developed that held the cover on two knife points and inside and outside were painted one side first and next side later and then the cover is put in the oven. Production doubled with the same facility.


Even though, the description of problem solving process, and process analysis are given in this note, the main work of Barnes is research on principles of motion economy and he developed a full book on motion and time study.

Ch. 18. Motion Study, Mechanization, and Automation


Work that can be done better and cheaper by machines has to be done by machines only in work systems.

Barnes recommends that industrial engineers develop the automated method for each operation in the process. Further to it, in work systems design, it is recommended that the best manual method or the best combination of manual and machine method be developed and used as a basis for evaluating the automated alternative to do each element or each sub-operation.  - Barnes. [Automation, Low cost automation]

Interesting statements by Google


Google Productivity Engineer: You might love this role if:

You have an unwavering passion for, and focus on, polished products, engineering excellence, and productivity.
You've worked to automate and remove repetitive and manual tasks because inefficiency is one of your least favorite things.

Read to know about Google Engineering Productivity Department
Google Engineering Productivity Department - Evolution of the Department through Automation of Testing. Emergence of Software Engineering Productivity Engineer & Specialist.


Related Information
Methods Design Concept by Sakamoto
https://books.google.co.in/books?id=r0WEDgAAQBAJ&pg=PA377#v=onepage&q&f=true

Updated on 15 August 2021,  6 July 2021
22 June 2020, 9 June 2020, 26 June 2019, 10 August 2015






1 comment:

  1. Human Effort Industrial Engineering: Taylor's contribution to the whole problem of effective utilization of human effort.

    ReplyDelete