Etsuko Kusukawa

An Application of Confirmation Sample Control Chart in the High-Yield Processes and Its Economic Design

This paper presents a modified CS(Confirmation Sample) chart for detecting sensitively small or moderate changes in p for both of upward and downward shifts in highyield processes. The simplified design of the modified CS chart is done by applying the design method of the CS chart for the Shewhart-type charts to the CCC(Cumulative Count of Conforming)-r chart dealing with the cumulative count of items inspected until observing r nonconforming items. As r gets larger, the modified CS chart, named the CSccc-r chart, becomes more and more sensitive to small or moderate changes in p for both of upward and downward shifts, but the CSccc-r chart needs more and more observations to obtain a plotting point on the CSccc-r chart, so the cost is fairly high. In this paper, a simplified optimal economic design method for the CSccc-r chart is also proposed. For illustrative purposes, some numerical results for the optimal design parameter values are provided.

Analysis of supply chain coordination with profit sharing under clearance and disposal sale markets

For many years, optimal decision of supply chain between a manufacturer and a retailer with clearance sale has been discussed. However, the combination of above topic and profit sharing has been substantially discussed. In this paper, we present an optimal inventory policy for a supply chain with return handling and profit sharing. We assume that the product is sold in three consecutive periods: the normal sale period, the clearance sale period and the subsequent leftovers disposal sale period. Two systems are analyzed: (i) the decentralized system, (ii) the centralized system. In the decentralized system, decision is made to maximize the retailers expected profit. In the centralized system, decisions are fully integrated for the joint profits obtained from the sum of the individual partys expected profit. Under the situations, we also discuss a coordination effect of the manufacturer-retailer partnership based on profit sharing. The profit sharing is permitted only in the centralized system as the coordination effect between the manufacturer and the retailer. In numerical examples, the results of the coordination effect are shown, by comparing the expected profits of each player and the whole system in the decentralized system with those in the centralized system with profit sharing.

REBATE SYSTEM FOR QUALITY IMPROVEMENT UNDER SUPPLY CHAIN ENVIRONMENT

Abstract In this paper, utility of rebate for quality improvement in a supply chain environment is discussed. In the proposed rebate system, any suppliers can receive rebate according to their quality improvement ***from manufacturer/subsequent supplier. The proposed rebate system aims to urge any suppliers to not only improve quality level autonomously, but also minimize total quality cost so that the whole supply chain can run economically. Utility of rebate is investigated by comparing both quality levels and total quality cost in the proposed supply chain system with rebate with those in the existing supply chain system without rebate.

Mean-Variance Analysis for Optimal Operation and Supply Chain Coordination in a Green Supply Chain

It is urgently-needed to construct a green supply chain (GSC) from collection of used products through recycling of them to sales of products using the recycled parts. Besides, it is necessary to consider the uncertainty in product demand as a risk in a GSC. This study proposes the optimal operations for a GSC with a retailer and a manufacturer. A retailer pays an incentive for collection of used products from customers and sells a single type of products in a market. A manufacturer produces the products ordered by the retailer, using recyclable parts with acceptable quality and compensates the collection cost of used products as to the recycled parts. This paper discusses the following risk attitudes: risk-neutral attitude, risk-averse attitude, and risk-prone attitude. Using mean-variance analysis, the optimal decisions for product order quantity, collection incentive, and lower limit of quality level, in the decentralized GSC (DGSC) and the integrated GSC (IGSC) are made. DGSC optimizes the utility function of each member. IGSC does that of the whole system. The analysis numerically investigates how (i) risk attitude and (ii) quality of recyclable parts affect the optimal operations. Supply chain coordination between GSC members to shift IGSC from DGSC is discussed.

Impact of e-commerce environment on selection of sales methods considering delivery lead time of goods

In this study, we discuss a brick-and-mortar sales (the existing sales method through the sales channel 1) and an online sales under an e-commerce environment (the sales channel 2). We focus on each differences of goods return ratios and delivery lead-times to a customer through both sales channels for a selling period. Concretely, we consider a parallel sales method that the sales channel 2 is newly incorporated into the sales channel 1. In the parallel sales method, a manufacturer incurs returns processing costs and fixed system operational costs for both the sales channels. For an appropriate selection ratio to the sales channel 2, the additional system operational costs in the parallel sale method could be retrieved, and it could lead to improving the profit to the manufacturer. Utility of the parallel sales method is investigated from each difference of goods return rates and delivery lead-times between both the sales channels by comparing the expected profit of the manufacturer adopting the existing sales method with that adopting the parallel sales method.