過與不及的品質管控與改善活動都會導致企業競爭力下降。因為如果產品品質超過目標值，則代表企業投入過多的有限資源以致使利潤降低或資源排擠；反之若產品品質未達到目標值，則代表企業投入的資源不足以致使產品無法符合客戶期望且無法驗收。有鑒於此，本研究提出一個整合田口損失函數與層級分析法的軟體產品品質評估方法，以使用者品質觀點為主軸來量化表示過與不及的產品品質管控資訊。此外，我們亦透過個案情節模擬的方式來引導讀者瞭解本評估方法的應用步驟以及該如何處理實務上的應用挑戰：（1）品質指標的適用性及裁適準則與（2）田口損失值的分析觀點與管理意含。最後，建立在本研究的產出基礎上，本研究亦指出3個值得後續探討延伸的未來研究方向。

Excess or deficient quality control and improvement activities cause a decrease in enterprise competitiveness. The quality of a product surpassing the target value indicates that the enterprise has invested too many resources, resulting in lower profits and crowding out resources; whereas the quality of a product falling short of the target value indicates that the enterprise did not invest enough resources, leading to failure in meeting customer expectation and incapability of acceptance. In view of this, this study proposed a quality evaluation method for software products using integration of Taguchi’s loss function and analytic hierarchy process. Information on excess and deficient quality control was quantified and expressed mainly from user quality perspectives. In addition, we guided readers through the evaluation method and application process using case scenario simulation, as well as discussing how to handle application challenges in practice including: (1) the proper guidelines and appropriateness of the quality indicators, and (2) the analytic perspective and management implications of the Taguchi's loss values. Finally, based on the output of this study, we also proposed three future research directions worthy of further investigation.