透過實驗研究交期不佳之主因

Abstract

達交率對公司而言是個非常重要的績效指標，達交率高的公司擁有較大的競爭優勢；相反地，經常性延宕顧客訂單的公司，將會失去銷售機會與商譽。因此過去有許多學術上的研究和實務上致力於改善交期方法，但至今達交率低落的問題仍然存在。為了提昇達交率，部分公司把焦點放在降低變異，另一部分公司則把焦點放在改善生產管理的方法，而哪一項才是主要阻礙我們提昇達交率的原因呢？這著實很難從現實生活中得到驗證，但是可以在虛擬的環境中進行測試。因此在本研究設計一個含有三種情境的虛擬環境，藉由此試驗，收集相關數據，驗證變異或是生產管理才是影響達交率的主要原因。試驗時，各組需要七人來參加受測，總共有三十組，受測者的背景為業界人士與工業工程與管理背景的學生。 此試驗是在無變異零工式（Job Shop）生產的環境中進行反證，如果變異為主要造成達交率低落的原因，此時在本研究的情境一其達交率績效表現應屬不錯，但是試驗結果推翻變異為主因的假設，此外本研究的情境二與三證明了生產管理規劃與執行才是影響達交率之主因，同時從試驗的過程中得到提昇達交率的方法。

Due date performance （DDP）is an important index of performance to the company. If the company has high DDP, then it will have competitive advantage. On the contrary, it will lose the chance of sale and the reputation. Therefore, there were many academic researches and practical methods to improve poor DDP. But poor DDP still exists. In order to improve DDP, some companies focused on reducing variation, others focused on production management. What is the major reason blocks us to improve DDP? It is impossible to test in reality, but it can be tested in virtual world. So in this paper, an experiment with three scenarios is developed to collect data to support which one is correct. There are 7 persons in each team. And there are 30 teams from local companies and students who major in industrial engineering and management. They participated the experiment. Without variation of this experiment is a disproof in Job Shop environment. If the variation is the major cause to poor DDP, then the scenario 1 will has high DDP. The experimental results support that the mode of managing production planning and execution is the major cause to poor DDP. According to the cause, criteria of good solution to high DDP are also identified.