SUMMARY Two alternative approaches to part-period balancing (PPB) are modified for non-instantaneous receipt and compared in an experiment. Both models require a production adjustment to accommodate the gradual inventory buildup that occurs during the production run time. One of the models is based on the cumulative cost approach used in most PPB applications, whereas the other model utilizes the marginal cost concept that has been used effectively in some studies of part-period balancing under instantaneous receipt. The experiment involved 540 test problems with varying demand, production rates, and cost structures.