Throughput Accounting

I came across a question, which asked for the calculation of the throughput accounting ratio.

The production figure was greater than the units sold figure. I took this to mean that there was closing inventory.

The mark scheme totally excluded any figure for closing inventory of finished goods from the throughput calculation, it simply calculated: the revenue from the units sold minus the materials purchased and divided by the total factory costs. (Side note: there were no machine hours provided for the max hours of the bottleneck resource available and so the mark scheme and question did not allow for the throughput contribution per bottleneck hour to be calculated.)

1. When calculating the throughput accounting ratio, do we always exclude closing inventory of finished goods and, instead, calculate the revenue from the units which were actually sold less the material purchases, divided by the factory costs?

2. If there is ‘work-in-progress’ do these values need to be incorporated into the workings for the throughput accounting ratio?

You may have covered the points in the lecture, I have watched it three times, but I can’t pinpoint/make the connection here.

Thank you so much.