A 2015 analysis of this data showed that as times increased, output also increased, but only to a point. The output of each hour dipped to about 40 hours of work per week and then fell.
Study author Dr John H Pencavel, a professor in the economics department at Stanford University, suggests that there is a sweet spot in the number of hours each person works each week. "After a point (a point that probably varies across workers and their jobs), a more work time delivers more output (or better performance) if the worker is worked 30 hours a week than if the worker worked 40 hours a week, "he said via email.
Pencavel discusses both municipal workers in his book Diminishing Returns and Work: The Results of Long Working Hours. There he explained that workers typically put in more than 50 hours of work per week, and sometimes as many as 72. Pencavel's number crunching numbers in the weeks when maximum output was not the same in weeks when the hours are longest.  This means that, at some point, throwing a lot of time into the problem won't help – and running costs will only run.
It's not just about working hours. : The days off are just as important when it comes to productivity. Munition workers often worked for days in a row without breaks. The work on Saturday was quite normal, and Sundays were again shown as working days because of the war.
Occasionally, however, munitionettes need to be removed. HMWC collected data that covered both of these conditions and realized that a week of work without a day off would not benefit anyone. Increased output does not increase, and workers are dissatisfied.