The work should be organized so that the operator receives only essential information through the appropriate sensory channels and at the time and place needed. The information should be presented in a way that permits the operator to react to it in the optimum manner.
In the decision-making phase of a task, the work should be arranged so that interpretations and decisions will be as nearly automatic as possible. The number of choices which the operator must make at a given time should be as few as possible.
The work method should be so designed so as to enable the operator to perform the task in the shortest possible time and with the greatest ease and satisfaction. The number of body members and the number of motions should be as few as possible, and the length of motions should be as short as possible. The job should be so designed so that it results in the lowest energy expenditure and the least physiological stress, as measured by calories per minute and heart beats per minute.
R.M. Barnes, Motion and Time Study, 5 Edition