Sennosuke Kuriyama

Cost Analysis of a Remanufacturing System

This paper deals with a cost management problem of a remanufacturing system with stochastic variability such as demand, remanufacturing rate and discard rate. We model the system with consideration for two types of inventories. One is the actual product inventory in a factory. The other is the virtual inventory that is used by customer. We define the state of the remanufacturing system by the both of the inventory levels. It is assumed that the cost function is composed of various cost factors such as holding, backlog and some kinds of manufacturing costs etc. The expected average cost per period is obtained by numerical computation. We also consider some scenarios under various conditions using design of experiments and discuss the effects of the cost factors on the remanufacturing system.

Cost management system based on EUC concept

Abstract Based on the End User Computing (EUC) concept, this paper proposes a generic system using simple macro routines of a spreadsheet software (Microsoft Excel) that can be used in a practical way between the different users of each level of an organization. This system is not only for managers, but also for employees in order to supply common information and enable simulations and decision making in the scope of each levels responsibilities. As a cost accounting system model, this paper discusses the possibility to use it in 4 different departments : Purchasing, Parts-production, Assembly and Sales departments.

Studies of optimal ordering policies for perishable commodities

Abstract Problems associated with perishable or outdating products arise in many areas of inventory and production man agement. Many commodities exist whose value does not remain constant over time during transportation, holding stock, etc. Significant work has been done to describe optimal ordering policies for items which have a fixed lifetime. In this paper, per ishable inventory models subject to stochastic procurement leadtinie both on LIFO (Last In First Out) and FIFO (First In First Out) issuing policies are considered with cither zero or 1 unit leadtinie. First, assumptions and notation used throughout the paper are given. FIFO and LIFO models are then con structed, and the existence of the optimal ordering policies and theirpropertiesare clarified. Finally, significantresults are illustrated for the relationship among inventory on hand, delay probability of procurement and optimal ordering policies.