多期可替代維修備品存貨規劃模型之研究

Abstract

隨著近年來消費者意識抬頭與顧客滿意度要求提升，企業面臨的競爭壓力也隨之攀升，使得傳統由製造端到消費端單向的正向物流服務、產品價格競爭等競爭策略已經無法滿足消費者的需求，亦無法成為廠商的競爭優勢。相對的，消費者對於產品售後服務日益重視，促使良好的產品售後服務成為企業在激烈競爭中勝出的另一關鍵。 在眾多的售後服務契約裡，業界中常見的是提供消費者保固維修契約，這些保固維修契約往往是顧客決定是否購買產品的主要因素，另外，在許多產業中，其產品間某種程度上具有可相互替代之特性，因此，若企業能在提供保固維修服務時，納入產品間可相互替代之考量，不僅可減少維修備品缺貨的情況，縮短顧客等待時間，企業亦可提供成本更低的維修服務。 基此，本研究參考學者對於保固維修服務契約與需求替代之相關研究，結合台灣個人電腦產業商業模式與保固維修服務運作系統，以維修商成本極小化的觀點，建立一成本極小化之多期可替代維修備品存貨線性規劃模型，利用系統化的方式決定各維修備品間的替代組合與替代數量，並分析在面對不同的維修備品需求型態與品牌商供應限制型態之情境下，維修商採用維修備品替代方式可獲得之利益，以及維修商在替代模式下之總成本、替代數量與替代成本的變動。此外，考量到市場具有不確定性，本研究亦建構一滾動規劃下最佳訂購時機決策模型，說明維修商如何在滾動規劃排程下，決定最佳訂購時機。 根據實驗分析結果，維修備品間之替代確實可替維修商節省總成本與待補訂單成本，且在波動型需求與緊縮型供應型態之情境下，維修商採用備品替代可節省最多的總成本。而在需求波動較小且供應限制型態較寬鬆時，維修商在替代模式下之總成本、替代數量與替代成本為最低。

After sales services is getting more and more important. Companies would face more competitive pressure as customer have started to value not only products itself but also after sales service, which also implies that after sales service have became a key factor to help companies get out of competition. This made companies cannot simply use traditional strategy like price competitive strategy to satisfy customer’s needs and further to form a competitive advantage. Therefore, companies have to make effort in finding out new ways to satisfy customer’s needs with competitive cost structure. Among all after sales contracts, the most common contract type in business world is the warranty and maintenance contracts which play a important role when customers choosing products. There is a way for maintenance service provider to cut down on the inventory costs and to reduce stock-out rate, which is exerting the product substitution on providing maintenance service. Thus, my study referred to not only related research of product substitution and warranty service contracts but also the maintenance practice of personal computer industry in Taiwan, to build a multi-period inventory model of substitutable maintenance spares parts, which minimize total costs of maintenance service providers. The study shows that how this model can benefit maintenance service providers by systematically deciding which type of maintenance spares parts can be substituted and the volumes of substitution. Besides, experiment analysis is used in the study to know how a demand pattern of spare parts and a limit purchase amount that maintenance service providers faced will affect substitution volume, the best substitutable spare parts bundle and the total cost of maintenance service providers. The study also builds a rolling schedule model based on the above-mentioned model to deal with market uncertainty issue. According to the analysis result, using downward substitution to spare parts can really save total cost and backorder cost, in particular under the circumstances that demand pattern of spare parts has higher variation and maintenance service providers have a limited purchase amount in warranty contract.