人類在現今的生活品質要求逐漸提高，並且在購買產品的能力也隨之上升，因此在對於產品的各層面要求甚高，故此時製造商會藉由預燒試驗來剔除不良品，以防止不良品落入顧客手中。另外，隨著現代的產品可靠度不斷提升，使用傳統預燒試驗已不再如以往有效率地挑選出不良品，有學者指出藉由觀察產品的品質特性，能有效提升預燒效率，隨著時間的增加，產品的品質特性則會發生衰退，因此可以使用適當的衰退模型來進行品質特性配置，過去研究指出Gamma過程是一種嚴格單調性的隨機過程，本研究將會以Gamma過程之衰退模型應用於品質特性的配置，有學者曾發展衰退模型基於Gamma過程下的預燒策略，在其研究中曾提出了最佳產品分類切點以及最佳預燒終止時間，而本研究是以Tsai et al.(2011)研究為基礎，其在成本最小化的概念下於終止時間時決定一分類切點，進行良品及不良品的分類。而本研究認為僅以一個時間點做為決策，一旦時間點拉長，會使得預燒策略效率低落，時間點短，則會使得決策太過倉促且精確度降低，故本研究考量的兩階段動態預燒試驗，針對兩種Gamma衰退模型，以動態規劃為概念進行求解，提出最佳分類切點和以及最佳分類區間，使得在終止時間點前，以預先篩選的方式，將表現良好之產品預先通過測試，反之，衰退程度高之產品則馬上剔除，以達到節省成本以及提升預燒試驗效率為目標進行預燒試驗。

Customers have been requiring more and more for the product's quality nowadays. Due to the high standard for every aspect in a product, manufacturers would eliminate early failure or weak products by using the burn-in test, which could prevent the customers from getting the weak products. As the products reliability increases, the traditional burn-in test are not feasible for highly reliable products. As an alternative approach, we could use suitable degradation model to fit quality characteristic that is related to product's life. In this research, we propose a dynamic burn-in test procedure by removing weak units at the early stage of a test. Different from traditional burn-in test with only one measurement time, this research considers two stages of dynamic burn-in procedure. A mixed gamma process to describe the degradation path of the product, aiming two kinds of gamma degradation models, and find out solutions in the concept of dynamic plans. Decisions about finding an optimal cutoff point and optimal cutoff bounds are also discussed in this paper. A numerical example using parameters from past research efforts is also proposed for showing that our proposed method can significantly reduce the total test cost in a burn-in test.

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