近年來隨著經濟蓬勃發展，人類生活型態以大量生產、大量消費與大量廢棄 的方式，造成全球暖化與自然資源耗盡的危機。尤其電子資訊產品因功能不斷推 陳出新，產品生命週期縮短與汰換率提升，廢棄物累積速度劇增，若無適當的處 置將對環境造成嚴重的負擔，因此提升廢棄物回收量以及促進資源有效再生、循 環使用實為當務之急。根據我國環保署回收基管會統計顯示，台灣地區筆記型電 腦產品回收率僅有1%，多數消費者將廢棄不用或汰換下的筆記型電腦存放家中或 直接丟棄，而未及時進行回收處理，導致收集率偏低之外，收集到之產品大多因 功能過時無法被再使用，降低產品殘餘的價值。有鑑於此，本研究從不同消費者 使用頻率建構時間函數評估模式，以價值工程（Value Engineering)以及產品生命 週期（Product Life Cycle)之觀點，探討消費者持有時間下獲得產品價值與付出總 擁有成本之關係，找出產品最佳回收時間，提供不同消費者做為產品回收之參考。

In recent years, human lifestyle under the rapid growth of economy requests mass-production, mass-consumption and mass-disposal. This change has led to the crisis of global warming and natural resources exhaustion. In particular, electronic consumer products have shorter life cycle and quicker replacement rate for their newest functions required, causing lots of used products. For those used electric products, if they are dumped without proper processing, great damage would be caused harmful to our environment. Actually, a great amount of useful resources could be recycled from these used products. Therefore, it is essential to increase take-back rate and to reuse these so-called waste effectively. According to the EPA of Taiwan, the take-back rate of notebook computer is very low, at only 1%. When new replacements are purchased, consumers usually keep their old computers at home instead of recycling them right away, which results in low re-collection rate and loss of residual value for the used products. In this study, an assessment model of customer value based on the idea of value engineering from the perspective of product life cycle is developed, and the relationship between product value and total cost of ownership (TCO) over the time with consideration of different user models is also explored. Furthermore, notebook computer is taken into consideration as an example to determine the optimal holding period. The results of this study could serve as a reference for different consumers to decide when the optimal time to recycle a product is.