Inventory models for both deteriorating and ameliorating items

Most of the previous works on classical inventory models are based on the assumptions that the value (or utility) of inventory remains constant over time. In this study, a special case of inventory model is studied for both ameliorating when the items stay at breeding yard (fish culture facility or farming yard) and deteriorating when the items stay in the distribution systems. The term ameliorating inventory is used in this paper at least since the terminology is not standard well known. First, We have developed economic order quantity(EOQ) models for both deteriorating and ameliorating, second we have developed partial selling model(PSQ) and economic production model(EPQ) considering issuing polices, FIFO and LIFO. Also we have developed computer programs and numerical examples to illustrate the model are examined also. (C) 1999 Elsevier Science Ltd. All rights reserved.