An economic lot-size model for deteriorating items with lot-size dependent replenishment cost and time-varying demand

In a recent paper, A.K. Bhunia and M. Maiti [Appl. Math. Modelling 23 (1999) 301-308] developed an inventory replenishment model for a deteriorating item with linearly time-varying increasing demand, lot-size dependent replenishment cost, and equal replenishment cycles. However, their analysis contained mathematical errors. Here, Bhunia and Maiti's (BM's) problem is firstly reconsidered by relaxing the assumption of equal replenishment cycles. A further extended model is developed for a general continuous time-varying demand. Then, the correct theory for BM's model is presented as the special case of the proposed model in this paper. Several numerical examples and sensitivity analysis for parameters are included. (C) 2000 Elsevier Science Inc. All rights reserved.