Process IE Methods - Part 3. Process Charts, Maps, Diagrams and Operation Analysis Sheet

Process Industrial Engineering - Methods and Techniques - Part 1 -  Part 2 -  Part 3 -  Part 4 -  Part  5

Lesson 75 of Industrial Engineering ONLINE Course.

Part 3: Process Industrial Engineering - Methods and Techniques - Process Charts, Maps,  Diagrams and Operation Analysis Sheet

Lesson 76. Process IE Methods - Part 4. Recording Operations Using The Motion-Picture Camera and Video Camera

Maynard & Stegemerten (1939)

Process Charts. A process chart may be broadly defined as any charted presentation of information connected with a manufacturing process or any other engineering process or business process.

Process charts, however, were originally designed by Frank B. Gilbreth for industrial use.

The information that is presented in the  process charts along with the steps in the process can include any or all of such factors as time for  operations performed, machine time,  motions used, operator time,  working and idle time of machines, cost, production data, time allowances, distance moved, and other similar data.

Use of Process Charts. The process chart forms a convenient means of presenting in a limited space information about a process. It shows operations performed in a process. It can be used to show the relation among operations, the steps of a process, and several sets of data. It permits the quick visualization of a problem so that improvement can be undertaken systematically and in logical sequence. it is a means of preparing data for study so that those who are making the study can grasp the problem at a glance and proceed toward its solution without wasted effort in each observing and understanding the process. If  a process chart is first prepared and every member of the group is given a copy to study, the discussion will start at the beginning and proceed systematically toward the end.

Progress is rapid, and little time is wasted by the discussion going off at a tangent.

The detail of the process study depends entirely upon the job under consideration. There is no fixed form of process chart that is rigidly adhered to by all methods engineers, or even by any one engineer. The chart is varied to suit the nature of the study that is being made and the data that it is desired to present.

There are, however, certain major types of charts that,  are widely used for methods-study work.

1. Operation process charts.
2. Flow process charts.
3. Man and machine process charts.
4. Operator process charts.
5. Progress process charts.
6. Miscellaneous types.

Operation Process Chart

On the operation process chart are usually shown:

1. The input materials.
2. The operations.
3. The inspections.

4. The time allowances for both operations and inspections.

Other information such as machine or work-station identification, male or female labor, pieces per hour, and the like, can be given if desired. The four items listed above are practically always required for any methods study and should always be recorded upon the chart as a matter of standard practice.  It is to be noted that as part of method study first time study of each operation/inspection needs to be done. Then productivity improvement implies reduction of the time taken. It is a simple matter to add other information to the chart if it is desired (More information needed has to be added. For example what are defects found after inspection. Why is it important? To eliminate waste. Defects are waste and if inspection activity identifies more defects, operation has to be improved to increase productivity).

Operation process charts are drawn on plain paper of sufficient size to accommodate the information that must be recorded. Two steps and  two standard symbols (Operation and Inspection) are used. The symbols are useful for distinguishing at a glance between operations and inspections without the necessity of reading the detailed information given on the chart.

If an operation process chart is drawn up as the first step of a methods study, it insures that the study will begin at the right point which is the first operation and proceed systematically to the last operation.

The flow process chart

When it is necessary to show in detail the exact manner in which a process is performed, describing what happens between operations as well as the operations themselves, the flow process chart is more suitable. This is desirable on certain types of studies, but on others the mass of detail would be too great for ready interpretation. The operation process chart shows the problem more clearly. If after a preliminary study more detailed information is desired, flow charts can be made for the various parts that make up the complete assembly.

The flow chart shows the different steps of a process such as operations, inspections, distance traveled, cessations of travel. The material of which a product is made is more commonly the item that is studied by flow charts;

Symbols Used for Flow-chart Construction. The earlier flow charts used about 40 different symbols to indicate the nature of the steps portrayed. Experience has shown, however, that too many different symbols detract from the clearness of the chart besides adding to the mechanical difficulties of chart construction, and modern practice therefore calls for the use of but six symbols. Sixth one, Denotes movement or operation outside the control of the investigator.

Time estimates for operation step is normally available. Time consumed by transportations may be determined by brief time study. lIn certain studies, time spent in temporary storage is one of the most important factors, for these studies are made primarily to decrease the time required to complete the process. Hence, it is important to have correct temporary storage data if improvement is to be made.

Operation- and flow-process-chart construction need not be limited to methods engineers. The charts can be constructed by anyone who has a problem to solve and who is willing to take the time to understand and apply the comparatively simple principles of process-chart preparation. Certain more progressive plants have given courses in methods engineering to their key supervisors and they are using them.

After process level analysis, a refined analysis needs to be performed upon the operations themselves. With the general nature of the problem understood and with the major inefficiencies either recognized or eliminated, the analyst is in a position to begin a study of each operation involved in the process with the idea of improving upon the operations themselves. This analysis requires more information and operation analysis sheet needs to be used.  Two other types of process charts  (Man and machine process charts and  Operator process charts)  are usually constructed only after a detailed analysis of the factors that surround a given operation have shown that they are needed.

Operations Analysis

Process charts show operations involved in a process. Operations are to be improved individually after process level improvements like eliminating waste or non value added operations are removed and sequence of operations is altered to derive productivity benefits. For doing operation improvement, more detailed information about the operation has to be collected and recorded. Maynard and Stegemerten descried the complete procedure of operation analysis and operator information sheet.

Operation analysis was already covered in an earlier lesson.

Operation Information sheet is described in Lesson 82. Operation Information Sheet for Productivity Analysis of Processing Operations

Process Charts and Other Recording Devices - R.L. Barnes (1931).

“Process charts are used to record in a simple, compact form and to visualize the elements of a process in sequence and in relation to the entire process. They record present practice for the purpose of studying and analyzing the present practice and also serve in visualizing possibility processes which improve the present practice by (1) changing the sequence of elements, (2) eliminating elements, (3) combining elements, and (4) substituting or changing elements. “As a record of standard practice, the process chart serves as an authoritative and complete picture of the entire process. It is particularly useful as a teaching device and as a means of maintenance.

After the initial pioneers, Maynard and Barnes contributed significantly in process industrial engineering area. Studying their books is important for industrial engineers, especially post-graduates in industrial engineering.

I now feel production planning and control is a component of process chart analysis as far as process improvement is concerned. Industrial engineers have to improve production planning routines as part of process chart analysis. Such an emphasis is not there in IE curriculum, as process chart is method is taught in work study or time and motion study courses.

Important points in the Lesson

Maynard & Stegemerten (1939)

Process Charts. A process chart may be broadly defined as any charted presentation of information connected with a manufacturing process or any other engineering process or business process.

The information that is presented in the  process charts along with the steps in the process can include any or all of such factors as time for  operations performed, machine time,  motions used, operator time,  working and idle time of machines, cost, production data, time allowances, distance moved, and other similar data.

If  a process chart is first prepared and every member of the group is given a copy to study, the discussion will start at the beginning and proceed systematically toward the end. Progress is rapid, and little time is wasted by the discussion going off at a tangent.

There are certain major types of charts that,  are widely used for methods-study work.

1. Operation process charts.
2. Flow process charts.
3. Man and machine process charts.
4. Operator process charts.
5. Progress process charts.
6. Miscellaneous types.

If an operation process chart is drawn up as the first step of a methods study, it insures that the study will begin at the right point which is the first operation and proceed systematically to the last operation.

When it is necessary to show in detail the exact manner in which a process is performed, describing what happens between operations as well as the operations themselves, the flow process chart is more suitable.

The operation process chart shows the problem more clearly. If after a preliminary study more detailed information is desired, flow charts can be made for the various parts that make up the complete assembly.

Time estimates for processing operation step is normally available. Time for other operations may be determined by brief time study.

After process level analysis, a refined analysis needs to be performed upon the operations themselves.

This analysis requires more information and operation analysis sheet needs to be used.

Process Charts and Other Recording Devices - R.L. Barnes (1931).

“Process charts are used to record in a simple, compact form and to visualize the elements of a process in sequence and in relation to the entire process."

Lesson 76. Process IE Methods - Part 4. Recording Operations Using The Motion-Picture Camera and Video Camera


Updated on 27.6.2022,  13 August 2021,   1 August 2021,  3 August 2020
First published on 31 July 2020