throughput – when to use minutes/when to use hours in ‘return per hour’

TPA ratio = Return per factory hour/Cost per factory hour

If the question specifically asks for “return per factory hour”, then make sure the final figure are in per hour. If it only asks for the TPA ratio, it does not matter as long as the return per factory hour and cost per factory hour are in the same form.

For example, return per factory hour/cost per factory hour should give the same TPA ratio as return per factory minute/cost per factory minute.

Sometimes the figures provided in the question are already in a “per hour” form so there’s no need to divide it by the time on key resource. Read the question carefully as I’ve seen it in exam questions where they give the figures as per annum, per week, per minute, per unit (you will need to convert it so return per factory and cost per factory are in the same state)

If you can, please provide reference to the questions you are referring to