Fatigue Study and Waste.

In “Motion Study” we stated: “There is no waste of any kind in the world that equals the waste from needless, ill-directed, and ineffective motions.”[1] It is an aspect of wasted motions that we are discussing here. Wasted motions mean wasted effort and wasted time. One of the results of this waste is unnecessary fatigue, caused by unnecessary effort expended during time that must, as a result, be wasted. Time, a lifetime, is our principal inheritance. To waste any of it is to lose part of our principal asset. To waste time and to suffer from unnecessary fatigue simultaneously can be excused only by ignorance. Unnecessary fatigue is caused by some one’s ignorance. This book aims to call the attention of the world to the relationship between fatigue and waste, with the hope that the knowledge of our methods of fatigue elimination may be useful to others.

What Fatigue Is.

A crowd of workers come out of the factory after the day’s work. Some rush home; others walk at a leisurely pace. Some move slowly and with effort. Some have their heads back and a satisfied expression on their faces. Others have their heads bent forward, and look as though life were not worth while. What is the difference between the members of this group? Mainly a matter of fatigue. Fatigue is the after-effect of work. It is the condition of the worker’s organism after he has expended energy in doing something. It is a necessary by-product of activity. If, as is presumable, every member of our crowd of workers has been putting in a day full of activity, we might expect to see the same marks of fatigue on every face and figure,—but we do not.

What, then, are the reasons for the difference? The state of fatigue has only been systematically studied during the past thirty years. Even to-day it is not wholly understood. We do know, however, several things about it, that may explain what we see in the emerging group. We know that fatigue is marked by a decrease in power to work, a decrease in pleasure taken in work, and a decrease in the enjoyment of the hours spent away from work. We know that exertion not only uses up temporarily the energy of the body, but that it also seems to generate a sort of poison which “slows one down” for the time being. In the third place, we know, also, that the effects of fatigue are more difficult to overcome as the fatigue becomes greater. Careful observation and records show that a little fatigue is easily overcome if proper rest is supplied immediately. Twice the amount of fatigue requires more than twice the amount of rest. Four times the amount of fatigue demands much more than twice as much rest as the preceding “more than twice the amount of rest,” until, finally, a state of excessive fatigue requires a rest period that might have to be prolonged indefinitely. It is this fact that lies at the basis of the great unnecessary waste in accumulated fatigue.

The trouble with these tired workers, then, is that their work has not been arranged in the least fatiguing manner nor in such a way that they could get the most rest and recovery in the least amount of idle time during the working hours. The ones whose heads are high and whose shoulders are thrown back may have been provided in some way with sufficient rest. The ones whose heads are bowed probably have not had the recovery time that they needed. It is possible that those who have had all the rest they needed have not produced as much as have the others. The remedy for this may not lie in shortening the rest, but in improving work methods. The waste in work not done, or in work done with the wrong method, is a serious economic waste. The waste in unnecessary fatigue is not only an economic waste, it is a waste of life, and it calls for immediate attention from every one of us, whether interested in the individual, the group, or the economic prosperity of our country.


What Fatigue Study Is.

Our fatigue study is an attack upon this unnecessary waste of human energy. It is a careful consideration of the problem of activity from the side of its results upon the human organism. It aims:

1. To determine accurately what fatigue results from doing various types of work.

2. To eliminate all unnecessary fatigue.

3. To reduce the necessary fatigue to the lowest amount possible.

4. To provide all possible means for overcoming fatigue.

5. To put the facts obtained from the study into such form that every worker can use them for himself to get more out of life.

The Field of This Book.

The reader who will carefully watch the tired crowd of workers will probably decide that he would like to do something about the fatigue problem immediately. There are various methods by which he may attack the problem. He may, and must, ultimately, review the literature on fatigue. The work of Marey, of Amar, of Imbert, of Offner, of Thorndike, and of numerous other physiologists and psychologists lies open to the student of the subject. He may turn immediately to Miss Josephine Goldmark’s masterly volume on “Fatigue and Efficiency.” This will give him an insight into the application of fatigue elimination to the industries. He may decide, however, that such study must wait, and that he must actually do something to cut down the fatigue the first thing the next morning, while the driving force of what he has seen is still strong. Nothing can mean so much to what he is to do as the strong incentive that drives him to doing it, the desire to help. But he will do best if he is instructed and directed. He should plan, in order that he may do the most in the least amount of time, and do the big, easy, obvious things first.

This book will outline a method of attack, and furnish a working practice for attacking the fatigue problem in an industrial plant. This practice is recommended because it rests on the results of measurement. We have here not simply a collection of illustrations that show what has been done in eliminating fatigue in the industries. All fatigue elimination is to be commended, but illustrations that do not embody well-recognized principles are questionable models. It is easy to make external changes that never touch the underlying cause of evil. Worthwhile, permanent fatigue elimination goes at the fundamentals of the work itself, and studies these in relation to the fatigue. What has been done is worth while when we know how it has been done, and why it has been done. Given these facts, we can determine how it may be done again in the same fashion and possibly even better. The practice that is the result of accurate measurement,—this is the standard to be demanded.

The Relation of Fatigue Study to Measured Functional Management.

Fatigue study is founded on measurement. This makes it an integral part of measured functional management. This is management that acts in accordance with standards. These standards are derived by actually measuring accurately what is happening. Standards contain the results of the measurement combined into new working methods. These standards are maintained only until they can be improved, when the new ones are in turn measured and maintained. Such accurate measurement demands that the problem of management be divided into measurable units. These units are made as small as possible, and constantly smaller as time goes on. It was the great work of Doctor Taylor to divide an operation, that is, a piece of work to be measured, into units for timing with a stop watch, and to separate rest units from work units.

From its beginning, Scientific Management has recognized the importance of the part played by fatigue. This recognition helps to obtain that co-operation and permanent beneficial efficiency that are the underlying ideas and the maintaining forces in this type of management. But fatigue study has only recently been acknowledged as fundamental to the most efficient management. Any one can attack the fatigue problem in its present condition in the industries successfully. He has simply to apply measurement. He can do this without regarding the investigations and results of others, if he chooses, but he will progress faster and farther if he uses results already at hand, and improves on “the best that has been known and thought in the world.”

Relation of Fatigue Study to Motion Study.

Motion study has been described as the dividing of the elements of the work into the most elementary subdivisions possible, studying and measuring the variables of these fundamental units separately and in relation to one another, and from these studied, chosen units, after they have been derived, building up methods of least waste. It is through the measuring of motions that one comes to realize most strongly the necessity of fatigue study.

There has come, in the past twenty-five years, a strong general realization that the important factor in doing work is the human factor, or the human element. Improvement in working apparatus of any type is important in its effect upon the human being who is to use the apparatus. The moment one begins to make man, the worker, the centre of activity, he appreciates that he has two elements to measure. One is the activity itself. This includes the motions, seen or unseen, made by the worker,—what is done and how it is done. The other is the fatigue. This includes the length and nature of the interval or rest period required for the worker to recover his original condition of working power.

Any one who makes real motion study, or analyzes motion study data, cannot fail to realize constantly the relationship of motion study to fatigue study. The fatigue is the more interesting element, in that it is the more difficult to determine exactly. When we recognize this close relationship between motion study and fatigue study, we see that we have a body of data already collected and at our disposal. What is even more desirable, we have a method of measurement ready at our hand. Every observation of a motion may be used to give information about fatigue. Is this information of immediate use to the man who is attacking his fatigue problem for the first time to-day? Yes, and no. Yes, in that it is at his disposal. No, in that he must determine his own particular problem before he can start to solve it. The first step in this direction lies in classifying fatigue.

The Classes of Fatigue.

There are two classes of fatigue:

1. Unnecessary fatigue, which results from unnecessary effort, or work which does not need to be done at all. A typical example of such work is that of the bricklayer, who furnished one of the first subjects for motion study. Any one who has watched a bricklayer lift all of his body above the waist, together with the bricks and mortar from the level of his feet to the top of a wall, cannot fail to realize that bricklaying requires a great amount of energy as well as skill. Yet by far the most of the energy expended in the method of laying bricks, that had existed for centuries, was entirely unnecessary.[2]

2. Necessary fatigue, which results from work that must be done. The new method, which enabled this same bricklayer to lay three hundred and fifty bricks per hour, where he had laid one hundred and twenty bricks per hour before, did not eliminate, and did not expect to eliminate all of the fatigue accumulated in the working day. The bricklayer at the end of the day, by reason of motion study devices, laid more brick, but was nevertheless much less tired. Experimental work in his case was carried to a high degree of perfection, because he was recognized as a splendid type of efficient brawn.

The Problems of Fatigue Study.

The problems of fatigue study are, then, four, which may be stated in very simple terms:

1. To determine what fatigue is unnecessary.

2. To determine what fatigue is necessary.

3. To eliminate all unnecessary fatigue possible.

4. To distribute the necessary fatigue properly, and to provide the best possible means for speedy and complete recovery.

The Methods of Fatigue Study.

The methods used must rest on a scientific basis. These methods are the same for the expert and for the man making his first attack on the problem. They are as follows:

1. Record present practice, make an accurate and complete account in writing of what is actually being done.

2. Decide in what sequence things are to be measured, and put them in such shape that they can be measured.

3. Apply accurate measurement.

4. Determine standards synthetically from the measurement, and make such changes in practice as will make it conform to the standard.

5. Compare the new standard practice with the old practice. Determine exactly what improvements have been made, in order to be able to predict the line along which new improvements must lie.

This is the standard method of attack of measured functional management. It can be the more successfully applied to fatigue study in that the results can be checked at every point by the results of motion study, which bear a constant relation to them.

Emphasis in Fatigue Study.

Any such study as this demands an emphasis upon accuracy. The man making the study must have a strong desire for finding and writing down the facts. He must have willingness to submit every aspect of the problem he is studying to the test of accurate measurement. Along with this desire for facts must go a realization of how the facts are to be used. Fatigue study is a constructive study. It builds up. It uses such terms as “elimination,” but its fundamental aim is conservation, and this conservation includes adding to those things which make life worth while. The desire to act as a force for betterment must be the incentive that makes the man doing fatigue study ready to record and face the actual facts.

A Work for Every One.

Recording facts is difficult work, but there is no one who cannot do some of it. It is the duty of every man to face the facts with which he works and to record them. You have come from the crowd of tired workers with an incentive to do this. Here is the method by which it may be done.



Fatigue study is related to motion study in that both are branches of waste elimination. Fatigue study classifies fatigue, and outlines methods by which unnecessary fatigue may be eliminated and rest from necessary fatigue may be provided.


[1] See “Motion Study,” p. 2.

[2] See “Bricklaying System,” chapter xiv. Myron C. Clark Co., Chicago.