- 學位論文
考慮產品不良率變動與預防維護策略於最佳化JIT生產與運送批量模式
Considering the Varying Defect Rate and Preventive Maintenance Policy in the Optimal JIT Production and Delivery Lot Size Model
摘要
由於傳統的經濟訂購批量與經濟生產批量模式其先天的基本假設與限制條件過多，較不符合現實情況，導致實用性太低。因此許多學者也開始放寬其基本假設與限制條件或是和其他相關議題來做結合，使得模式更加符合現實情況。 在現今競爭激烈的市場環境中，要提升競爭力除了降低成本外，還可以透過合作夥伴的關係，互相協商，因此及時生產系統（Just-in-time, JIT）的概念成功的被運用在業界。同時產品的品質水準也是競爭的重點，在傳統的存貨模式中，皆不考慮不良率或設其為一固定常數。然而在現實情況中，生產設備在經過長時間的運轉下一定會有損毀的情況發生，導致不良率的提高，必須定期的對設備進行維護，才能使生產設備處於一個可靠的狀態。同時所生產出的不良品可以透過重新加工，使其變成良品。 因此，本研究綜合上述的問題，加入考慮產品不良率變動、預防維護策略與重工，重新提出一個含JIT生產與運送的整合性二階層的存貨模式，以決定出最佳的生產批量、運送次數與維護間隔時間，使得聯合總成本為最低。
並列摘要
Traditional Economic Order Quantity and Economic Production Quantity models reduced their practicability because the basic assumption and limited terms are too much. Many researchers started to loosen the basic assumption and limited terms or combine other topics for making the model useful in real environment. In a competitive market environment, increasing the competitiveness of a business is not only reducing cost, but also enhancing partnership with others. Therefore the Just-In-Time system is successfully used in industrial circles. At the same time the product quality level is the key point of competition, but in traditional inventory model, it usually doesn’t consider the defect rate, which is a main issue of product quality. Also, in real environment, the machine will breakdown under long running time and increase defect rate, so preventive maintenance policy is necessary to make machine in a reliable state. In the meantime, reworking the defective item also becomes an important topic in inventory model. This study integrates the above questions including varying defect rate, preventive maintenance policy and rework. An integrated two-echelon inventory model to decide the best production quantity, delivery frequency and preventive maintenance interval under JIT production and delivery policy is proposed. As a result, the total cost can be minimized.