Key points are not available for this paper at this time.
Summary Probability concepts are applied to determine the extent to which the productivity of machines is reduced when one operator has charge of several so that, whenever two machines stop at about the same time, one has to stand idle until the operator has re-started the other. For the case when the requisite attention times for each re-start are equal, a table of the average number of machines running and a chart showing the most economical ratio of machines to operators have been prepared.
H. Ashcroft (Sun,) studied this question.