The New Zealand Railways Magazine, Volume 5, Issue 2 (June 2, 1930)
Industrial Psychology — Standardisation and Motion Study
In the following instalment of Mr. Dale's series of articles on Modern Industrial Psychology, interesting reference is made to experiments in methods of standardisation, and in motion study, in relation to increased production.
The Meaning of Method in Modern Industry
It is, apparently, very easy to schedule and route work, as explained in the previous article, but it is, in point of fact, merely the preliminary survey, if methods of manufacture, modes of procedure, and kindred problems have not been sifted, strained and standardised. From a restricted survey in this country, it is the writer's opinion that from this aspect factory technique is still behind the standard attained in factories both in the Old World and in America. I have noted facts where the Railway Workshops have, to a considerable degree, secured this standardisation with some excellent results, as output schedules will show. This is obtained, however, only by adopting new methods of work in direct correlation with motion study, micromotion study, cyclegraph studies and chronocyclegraph records. This formidable array of technical terms arose as the result of studies in early scheduling, and their use will be apparent as soon as the problem is examined in all its bearings.
Before the foreman can schedule time spent upon any phase of the “job” or contract, he must make a careful analysis of it. A reference was made to “clocking” the employee, that is, checking the amount of time taken to perform a series of movements necessary to complete the work. This is taken with a stopwatch. It is, nevertheless, insufficient, for it includes the time taken over movements which are, in themselves, unnecessary, or, technically “aimless.” (See illustration No. 2 A.) This is due to lack of analysis therefore, and for this very reason psychologists stepped in with motion studies. Each set of movements is analysed into the simplest single motions which from part of the whole process. These motions are timed, and a large number of “times” are averaged to give a fairly standard result. To the average person this may sound unimportant, but with a split-second watch there is the time of stopping the watch, the time used in connection with handling machinery, and the “human” factor which, at best, is not infallible. To make allowances for these divergences, the average time for the same movement is taken as against one “clocking.” At the same time it will be evident what is meant by waste or aimless movement if we consider how a hand is moved across the body. It may be moved straight across, across lower down, say just above the knees or breast high. It is plain that the movement in a straight line will be quicker in point of time, and less fatiguing over a period of time. The aim is to scrap wasteful movements. The problem at once arises: How can this be done? The best workman may not, necessarily, be using the straightest movements. Because his output is in advance of that of others it does not necessarily follow that he is using perfect motion. Research indicated all sorts of imperfections, so that it was on the movements of the best worker, when corrected, that the earlier motion methods were based.
It soon became manifest that forms of movement could not be recorded with sufficient precision by merely observing them. It became necessary to record these so that recourse was made to the cinematograph, and a Gilbreth clock, which registers extremely minute divisions of time, smaller than the elapsed time between any two pictures of the film. Gilbreth himself stated that this method enabled him to record easily, motions down to less than a ten-thousandth of a minute. The obvious result is freedom from error, guessing, and the personal element. Here again the psychologist baulked. True, the workman could see himself at work, but it was still relatively difficult to teach from such a record. At the same time there were inherent difficulties, such as the workman obscuring page 35 a view, or performing movements where the camera could not film them. Both of these factors rendered the method unsatisfactory, as the film was intended for “teaching” efficient methods when they had been constructed and taught to one specific worker.
To overcome these drawbacks use was made of the “cyclegraph.” This apparatus consists of a small electric light attached to the hands, or any other member involved in the process. A photographic plate or film is exposed throughout the time the motion is being studied, with the result that a path of light resembling a white wire is seen upon the plate. This white line represents the motions used during the observed process. Later it was used with a stereoscopic camera to show the path in three dimensions. This record, however, lacks the time element. It is quite impossible to know from this record the time occupied in the motion. There came the difficulty of correlating time and motion, which earlier investigations had combined. This defect was then overcome by using a tuning fork, which, vibrating at a known speed, was connected with a “make and break” contact. This device gave the motion in dashes, and as each dash represented a definite space of time, any portion, or even the complete motion could be determined in a time name. (See illustration No. 2 B.) It further indicated the relative speed of different parts of the motion. It will at once appear that dashes in close proximity indicate quicker movement than those with a greater distance between.
All difficulties were not yet overcome, however. It was still necessary to determine direction of movement and length of such motion. To aid in detection of these factors, Gilbreth made use of additional material, and called the unit a chronocyclegraph. The direction was noted on the plate by means of arrow-heads. (See illustration No. 2 C.) These pointed in the direction of the path travelled from the point of origin. It was now possible to measure time motion and direction. To record the distance was less easy, and involved the use of the “penetrating screen.” The space to be photographed was backed by a large sheet of black paper cross-sectioned with white lines at predetermined distances from each other, and then photographed on the spot where movements were to be studied. When exposed, the plate was removed and then used a second time to record the moving light. When developed the negative showed a “motion curve” on a background of cross-sections. (See illustration No. 2 D.) The spatial distance between the intersecting lines was already known, so that to calculate the distance travelled presented no difficulty. By this method we can now check four “variables” as they are termed, namely, length of movement, relative speed, time and direction of movement. (See illustration No. 1.) Using a suitable camera, we are thus able to view the whole process on three dimensions.
The latest extension on Gilbreth's idea is the “construction of a wire model based upon the cross-sectioned chronocyclegraph record. This shews the motion in three dimensions, and attempts to reproduce the precise length of the original movement and each of its parts. On this model are shewn also the arrow heads, so that from it the movement can be studied in as favourable a form as possible.”
Utility of the Research.
The explanation of these processes will no doubt cause the average employer to question the utility of the chronocyclegraph records (or even to ask why bother with such refinements?) holding that such minute details are not of practical use. However, the conclusions drawn from such studies in the workshops mean more work in less time, with less fatiguing results. The best known example which occurs at the moment is that of chocolate dipping. The preliminary investigations shewed a tremendous waste of motion in coating chocolate centres. The movements were reduced to, I think, six, and an immensely greater output resulted. Similar experiments were made in a certain well-known English soap factory. One instance will show the utility of these researches. page 36 The girls wrapping cakes of soap were not working under any organised system. Preliminary observations indicated seven to eight movements which, upon analysis, were reduced to three, at the same time, a rhythm of work was introduced which avoided fatigue.
The psychologist will analyse your processes and teach the workmen the new motions. This brings us to the next phase in organisation for schedules, namely, new “work methods.”
Effect of Habit.
Every workman has his own idea of how things ought to be done, and every shop has a tradition in respect to methods of work; these two factors taken into conjunction make it difficult to introduce new ideas. Recently an employee complained that if he were allowed to work along his own lines, as he did formerly, he could do “just as much if not more.” Granted that it would be so on broadest lines, the small matters would be unrealised, and often these are omitted in the analysis. If the foreman plans, then he must work to that plan without divergence. This entails “best way.” methods in order to keep to schedule. For this reason, in addition to motion studies, standardisation has been largely accepted as another axiom, agreeing, of course, with the belief that fatigue will reduce the output. To overcome this difficulty and enable the worker to earn more wages (if it is piecework) compulsory rest periods have been introduced.
Dr. Taylor's example is so well known that it will be given briefly. A large steel corporation in U.S.A. employed seventy unskilled labourers to carry pig-iron up an inclined plank and tip it into a waiting truck. The average amount shifted per worker per day was 12 1/2 tons. Pigiron was a cheap commodity, but the method of handling it was cumbersome, so Taylor was asked to investigate. At once he put his finger on the weakness. He showed the futility of saying a man was working only when carrying iron. Energy was being continuously expended in walking, lifting and even standing motionless with the iron “up.” He thereupon standardised the procedure of lifting and carrying. Next he broke the day up into work spells and rest pauses, so that in actual fact the men worked, as the average employer understands the term, only 43 per cent. of the day unit, when the pigiron weighed 92lbs. By decreasing the weight of the pig-iron by 50 per cent. he discovered that 58 per cent. of the unit was worked. The combination of motion study and rest pauses of ten minutes after seven minutes work increased the output from the original figure to 47 1/2 tons per man per day. This was practically a 400 per cent. increase, with less exertion than had been used formerly. This example does not, of course, indicate that men should do this form of work, machinery could do it much more easily, but it gives point to method.
(A) Represents the general character of a cyclegraph record shewing motion only; (B) is the motion record timed by a vibrating tuning fork. (The dashes represent a pre-determined interval.) (C) Shews the motion time and direction of the motion (note blunt arrow heads); (D) a complete chronocyclegraph as screened out by Gilbreth to shew motion, time, direction and length of motion.
Principle of Pauses.
The next example is that of a light occupation, namely, that of folding handkerchiefs. The method formerly in use was to have the workers seated at low tables in chairs of ordinary heights. The girls were paid at piece rates, so that they had rest only when going for fresh material or took finished products, together with a short pause for dinner. An intensive study of the problem was made in order to increase output as well as to provide better working conditions, so that the girls could earn more with less fatigue. To bring this about, the tables were raised to give a minimum effort in reaching for material. The handkerchiefs were kept in three piles, namely, those unfolded, those being page 37 handled, and those parcelled and checked—i.e., finished work. The hour was divided into ten periods, and the motions thoroughly taught, and completely standardised. For the first four periods—that is for twenty-four minutes—the girl remained seated, working five minutes and resting one minute, and so on for the period. Thus, in twenty-four minutes she spent four minutes resting in her chair at the table. During the next twelve minutes, she stood to her work, observing rest periods as before. For the next three sections of the hour, that it, eighteen minutes, she was at liberty to sit or stand just as she desired, but the girl was still compelled to rest at the end of five minutes' work. During the last period she did no work at all. Now, she might stand, walk, sit, leave the workshop—in short she was perfectly free to do just what she liked. The only exception to this routine was the hour before lunch and the last hour before closing time. During these hours, since there was a prolonged rest to follow, the last period of each of these two hours was spent in work. The result?—The output was three times what it had been before the reorganisation. Moreover, the observers noted about the girls an alertness which formerly was missing; they showed more interest in their work, and yet gave proofs of less fatigue, despite a 300 per cent. increase in output.
The last example is one given by the Munition Ministry's “Industrial Fatigue and its Causes.” A foundry, in which the workers were paid piece rates, was engaged on munition work. The management decided upon rest pauses, much to the disgust of the workers, who feared a loss in wages. It was decided that the moulders should rest a quarter of each hour. At first it was considered by the employees as an attack on their wages, involving a substantial decrease. Their argument was, of course, that shorter hours would involve less work, and hence less pay. After some time had elapsed, however, the moulders' pay indicated, in the modest words of the report, “a substantial increase in output.”
I think enough has been written to show that pauses do not hinder output, rather, they indicate an increase. That this is so is realised by clothing and shirt factories, where work is carried out only on five days a week. The obvious error is, however, found in the assumption that a long spell will overcome the accumulated effects of half-an-hour's extra work per day. This is an entirely erroneous assumption, and is far from scientific in its application. It would be better, perhaps, to keep to five days a week, but institute pauses during the day in combination with movements taught from motion study research.
The Opening Game of the Tour.
(Railway Publicity photos.)
The visiting British Rugby team won the opening game of its tour by defeating Wanganui (at Wanganui) by 19 points to 3. The illustrations shew: (1) The British team; (2) T. C. Knowles (Great Britain) is well tackled. J. C. Morley in support; (3) J. C. Morley (Great Britain) takes a pass, but is well marked; (4) W. H. Sobey (Great Britain) gets his pass away before being tackled by G. Walden (Wanganui); (5) A portion of the crowd; (6) P. Prince (Wanganui) makes a run; (7) The Press Table; (8) C. D. Aarvold (Great Britain) gets his pass, away to A. L. Novis; (9) P. Prince (Wanganui) attempts to break through; (10) T. C. Knowles (Great Britain) in action;. A. L. Novis in support; C. D. Aarvold well grassed; (11) The Wanganui team.
Wellington Public Libraries.
Incidents Throughout the Game.
(Rly. Publicity photos.)
From the above views, it may be seen that the game played between Great Britain and Wanganui was interesting and exciting. The illustrations shew:—(1) The Wanganui half-back (J. Duncan) breaks away from a scrum, while W. H. Sobey (Great Britain) is about to intercept; (2) the Wanganui full-back (D. Thompson) gathers in the ball; (3) a struggle for possession in a line-out; (4) T. C. Knowles (Great Britain) breaks through, with J. C. Morley in support; (5) I. Jones (Great Britain) saves from a Wanganui attack; (6) B. H. Black (Great Britain) place-kicking; (7) forming a scrum.