The Formation and Size of Process Inventory
When the product lot is manufactured through more than a single operation, the
process inventory builds up during the first operation and depletes during the last
operation. The formation of the process inventory varies somewhat under different
conditions and the length of the manufacturing cycle time affects its average size per
time unit. To find a general expression for the average process inventory, we will
examine the time-weighted process inventory per manufacturing cycle which will be
measured in unit X time. In the following illustration, the manufacturing cycle time
defined in (3) assumes sequential or pure combined movements when r = 1