Work is done most effectively and efficiently under good, comfortable working conditions.
Questions. The industrial engineering, during operation analysis, should consider the following points :
1. Is light ample and sufficient at all times?
2. Are the eyes of the operator protected from glare and from reflections from bright surfaces?
3. Is lighting uniform over the working area?
4. Has lighting been checked by an illumination expert?
5. Is proper temperature for maximum comfort provided at all times?
6. Is plant unduly cold in winter, particularly on Monday mornings ?
7. Is plant unduly warm in summer?
8. Would installation of air-conditioning equipment be justified?
9. Can fans be used to remove heat from solder pots, furnaces, or other heat-producing equipment?
10. Could an air curtain be provided to protect operator from intense heat?
11. Is ventilation good?
12. Are drafts eliminated?
13. Can fumes, smoke, and dust be removed by an exhaust system?
14. Is floor warm and not damp?
15. If concrete floors are used, can mats or platforms be provided to make standing more comfortable?
16. Are drinking fountains located near by?
17. Is water cool, and is there an adequate supply?
18. Are washrooms conveniently located?
19. Are facilities adequate and kept properly clean?
20. Are lockers provided for coats, hats, and personal belongings?
21. Have safety factors received due consideration?
22. Is floor safe, smooth but not slippery?
23. Is wooden equipment, such as work benches, in good condition and not splintery?
24. Are tools and moving drives and parts properly guarded?
25. Is there any way operator can perform operation without using safety devices or guards?
26. Has operator been taught safe working practices?
27. Is clothing of operator proper from safety standpoint?
28. Are workplace and surrounding space kept clear at all times?
29. Do plant, benches, or machines need paint?
30. Does plant present neat, orderly appearance at all times?
A brief discussion of a few of the principal factors:
Light, Heat, and Ventilation.
Light, heat, and ventilation are matters to be designed by the illumination and heating engineers. But, the industrial engineering can tell by personal observation when these conditions are bad, and he can point out the effect that they have on production. Accurate work, for instance, cannot be done in the dark and improper lighting conditions have to be corrected. In many communities, the utility companies provide experts who will survey lighting conditions and make recommendations without cost. Advantage should be taken of this service even where lighting to the untrained observer appears fairly good. Eyestrain is a serious matter and can and should be eliminated.
It has been shown conclusively by researchers that good working conditions pay. Although it is often difficult to measure directly and immediately the saving brought about by the installation of a new lighting or heating system, it is a good policy to recommend their provision wherever the present systems are found to be inadequate. Throughout industry, it is found that the plants which provide the best working conditions are those which are leaders in their field. This alone would indicate that the provision of good conditions is a profitable investment.
Safety engineering and methods engineering are closely related. The methods engineer is interested in labor efficiency and effectiveness. In order to work effectively, the operator must be able to concentrate upon the work at hand. If an accident hazard exists, however, he must divide his attention between doing the job and keeping out of danger. Therefore, the methods engineer is interested in the elimination of accident hazards.
As the result of his detailed study of all aspects of production, industrial engineering is in an excellent position to discover accident hazards and to make suggestions for their elimination. He studies every move made by the operator, and hence he discovers the moves that carry parts of his body into a danger zone. He "can then either eliminate the moves by changing the motion sequence or take steps to have the danger zone guarded.
A kick press equipped with a safety device and the operation analyst was informed that the device was foolproof, that it was the best safety device in the department. The analyst observed the operation of this safety device along with all the other factors of the job. In order to operate the kick press, the operator had to place the material in position, grasp the two bars, and swing them to one side. He then stepped on the treadle of the machine and performed the operation.
The operation appeared clumsy and inefficient to the analyst. Because the material could not be held in place by the operator, it tended to slide out of position. Clips were provided to hold it down, but to use them required so much time that the operator preferred not to do so. As a result, the material did slip out of position occasionally, and scrap was produced. The movements necessary to operate the bars carried the hands of the operator out of the danger zone, but they were fatiguing and time-consuming. A further investigation showed that the safety device could be circumvented very easily. If after making a stroke with the press, the operator did not allow the treadle fully to return to the off position, the bars rested in a position and there was plenty of room to draw material through the die. When the treadle was depressed again, the bars slid to the position in which small and inconspicuous block of wood affixed to the treadle of the machine would prevent it from returning to its off position, and hence the operation could be done easily without using the safety device.
The industrial engineers and the safety engineer, then proceeded to devise a new guard . This guard really is foolproof. The operator cannot get his fingers under the die in any way, but he has complete control of the operation at all times. As a result, the operation is safer and much faster than it was before.
Other Working Conditions
Space is provided on the analysis sheet for comments about any factors that affect the operation that have not previously been considered. The following list of questions will indicate the kind of items that should be considered at this point:
1. How is the amount of finished material counted?
2. Is there a definite check between pieces completed and pieces paid for?
3. Can automatic counters be used?
4. Is pay-roll procedure understandable?
5. Is the design of the part suitable to good manufacturing ' practices?
6. What clerical work is required from the operator to fill out time cards, material requisitions, and the like?
7. Can this work be delegated to a clerk?
8. What sort of delay is likely to be encountered by the operator, and how can it be avoided?
9. How is defective work handled?
10. Should operator grind his own tools, or should this be done in toolroom?
11. Should order department be requested to place fewer orders for larger quantities?
12. What is the economic lot size for the job being analyzed?
13. Are adequate performance records maintained?
14. Are new men properly introduced to their surroundings, and are sufficient instructions given them?
15. Are failures to meet standard performance requirements investigated?
16. Are suggestions from workers encouraged?
17. Do workers understand the incentive plan under which they work?
18. Is a real interest developed in the workers in the product on which they are working?
19. Are working hours suitable for efficient operation?
20. Is the utilization of costly supply materials checked?
It will be seen from the general nature of the questions listed above that the methods engineer recognizes his responsibility toward everything connected with the job he is analyzing. It will not satisfy him to say that the designs are made by the engineering department or that the shop routine is set up by the management. He realizes that his own intimate knowledge of shop methods and conditions gives him an advantage which many other members of the organization do not possess, and he therefore feels it his duty to question all phases of manufacture in the hope of revealing possibilities for improvement.
For example, a designer who is making a drawing of a steel shaft, having in its length several different diameters, knows how to lay out the shaft, taking into consideration strength, size, and suitability of purpose. He probably knows in a general way that the shaft will be turned on a lathe and that at the junction of two sections of different diameters it is better from the standpoint of ease of machining to call for a fillet with radius r as ia (a), Fig. 105, rather than to specify a squared-out corner as shown in (&) of the same figure. What he may not realize, however, is that for reasons of manufacturing economy, the fillet is machined with a specially ground tool, known as a "radius tool" which is the exact size of the radius to be turned. Therefore, if there are several fillets to be turned on the same shaft, he may call for, say one 1/4-inch radius, two 3/8-inch radii, and one 1/2-inch radius, being governed largely by the difference in the diameters of the adjacent sections.
If this incorrect and unnecessary feature of design is allowed to pass unchallenged, it means that three radius tools must be used instead of one. When the shaft is turned on an engine lathe, time for two extra " change tool " operations must be allowed. This is unnecessary and wasteful, and the design should be changed.
From the nature of the many examples of operation improvements that have been given throughout this book, it will be seen that if the analyst is to do his work so as to bring about maximum manufacturing economy, he must concern himself with every detail connected with every job he studies. Common sense, of course, must be used in interpreting this statement. In practical work, it means that the analyst should consider, at least briefly, every detail that is likely to affect operation time.
All analysis work is done for the purpose of improving the method by which the operation is done. The various factors that affect method directly or indirectly are considered in detail, and improvements are made wherever possible. As a result, many economies are made that eliminate motions and reduce costs.
Before the study can be considered complete, however, the motions that remain and that appear to be necessary must themselves be studied in considerable detail. It is not enough to say that a part is to be obtained by picking it out of the gravity delivery chute. The location of the end of the chute should be such that the hand can move between it and the point where the material is worked upon with the shortest and lowest class motion. The height of the chute should be such that the transport motions can be made without a change of direction. The motions used for grasping must be worked out so that the fewest possible are employed. If two parts are required, it must be decided whether they are to be grasped and transported together or separately. The best position of the hand and of the material in the hand must be determined so that no time is lost in positioning the material at the place of work.
In short, every motion must be analyzed in detail for the purpose of shortening it and making it as effective as possible. This, a secondary form of analysis, is known as motion study. Motion study is itself a detailed procedure which will require as lengthy a discussion as the subject of operation analysis. Therefore, it will merely be mentioned here that motion study is the next logical step in the methods study after operation analysis.
Full Knol Book - Method Study: Methods Efficiency Engineering - Knol Book
Modified and unpdated on 10 August 2016
Updated 4 July 2015, First published 24 Nov 2011