An economic lot-size model for deteriorating items with lot-size dependentreplenishment 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 i tem with linearly time-varying increasing demand, lot-size dependent replen ishment cost, and equal replenishment cycles. However, their analysis conta ined mathematical errors. Here, Bhunia and Maiti's (BM's) problem is firstl y reconsidered by relaxing the assumption of equal replenishment cycles. A further extended model is developed for a general continuous time-varying d emand. 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 se nsitivity analysis for parameters are included. (C) 2000 Elsevier Science I nc. All rights reserved.