Variables that Affect Fatigue.
We included in “Motion Study,”[4] a list of forty-two variables that affect motions. The list we use consists of one hundred and nineteen. We feel that our list is by no means complete. It is necessary only to note here that every possible change in the work, the worker, or the method has its effect upon the fatigue. This need not act as a deterrent from making changes. It need only act as a warning that no change made without a thorough consideration of every element of the problem can be of permanent value.