A Comment on Determination of Optimum Production Quantity for a Two-stage Production System

It has been suggested in the literature that unequal sub-batch sizes yield a lower cost than equal sub-batch sizes, for the same problem parameters. It is shown in this paper that the cost comparison that led to this conclusion is invalid because it is based on the same lot size and number of sub-batches for both cases. The two models would not necessarily yield identical optimal lot sizes and numbers of sub-batches. Perhaps more importantly, the effect of the relaxed batch-size constraint on transportation costs was ignored in comparing the costs.