OPTIMAL ORDERING POLICIES FOR DETERIORATING ITEMS WITH BACKORDERS

• Main Authors: Tsu-Pang Hsieh, 謝組邦
• Other Authors: Liang-Yuh Ouyang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/48603974435822320943

博士 === 淡江大學 === 管理科學研究所博士班 === 95 === The general assumptions in classical inventory models are that items can be stored indefinitely to meet future demand and the business owns a single warehouse without capacity limitation. In practice, it is well known that certain products such as medicine, volatile liquids, blood bank, food stuff and many others, decrease under deterioration (vaporization, damage, spoilage, dryness and so on) during their normal storage period. As a result, while determining the optimal inventory policy of that type of products, the loss due to deterioration can not be neglected. On the other hand, while a large stock is to be held, due to the limited capacity of the own warehouse, one extra warehouse may be required. In this thesis, three deterministic inventory models for deteriorating items have been formulated with backorders considerations. In Chapter 2, a deterministic inventory model for deteriorating items with price-dependent demand is developed. The demand and deterioration rates are continuous and differentiable functions of price and time, respectively. In particular, we allow for shortages and the unsatisfied demand is partially backlogged at a negative exponential rate with the waiting time. Following the assumptions about deterioration and demand rates, in Chapter 3, an infinite time horizon inventory model with time-value of money is discussed. In addition, we allow for shortages and completely backlogged. The objective is to find the optimal replenishment and pricing strategies maximizing the net present value of total profit over the infinite horizon. It is assumed that the capacity of the own warehouse is unlimited in Chapter 2 and Chapter 3. In Chapter 4, a deterministic inventory model is developed for deteriorating items with capacity constraint and time-proportional backlogging rate. A rented warehouse is used when the ordering quantity exceeds the limited capacity of the own warehouse. In all inventory models, the existence and uniqueness of the optimal solution are proved and numerical examples are provided to illustrate the proposed models. Finally, in Chapter 5, we provide some conclusions of this thesis and future research topics.