現今軟體開發的挑戰主要來自於需求與環境的改變。已開發完成的軟體仍需隨著需求與環境的變化而改變，才能夠持續上線服務。軟體重構是一項軟體維護與軟體演化的技術，能夠使軟體易於調整、改變。正如其他軟體開發活動需要一系列的決策支援，軟體重構的過程也需要客觀的評估分析，作為軟體重構決策的憑證。若缺乏足夠的決策憑證，軟體重構可能導致意料之外的影響，而使軟體品質受損。

軟體開發者在進行軟體重構時，必須了解何處需要執行重構方案，以及哪一個重構方案最適合解決目前的問題。目前對於軟體重構影響的研究並無法建立一個有效的評估模型，讓軟體開發者能夠預測重構方案帶來的效果並且進行全面的影響評估。因此，軟體開發者往往缺乏足夠的憑證來判斷是否需要執行軟體重構，以及挑選合適的重構方案。本研究深入探討軟體重構的影響，對於軟體重構流程有細部的分析，目的在於建立一個有效的評估模型，幫助軟體開發者進行軟體重構當中的決策。本研究亦建立了一個整合式的軟體重構環境，提供軟體開發者一系列重構決策所需要的工具輔助。軟體重構流程的細部分析結果將有助於重構方案的評估與診斷，並有助於軟體重構流程與其他軟體開發活動的整合。

The major challenges to software development nowadays come from the changes of requirements and environments. Refactoring is a technique for maintenance and evolution that makes software easier to change. Just as other software development activities that involve critical decision making, performing refactoring in maintenance and evolution needs evidence support to obtain desirable results. Otherwise, without careful estimation of refactoring effects, refactoring might also cause undesirable results.

Developers need evidences of where to apply refactorings and which refactorings to apply. Current studies on refactoring effects are not enough to come out with such evidences. The evidences needed to approve a refactoring proposition in the refactoring are not enough for developers to make judgement. This study provides a fine-grained analysis of refactoring effects to conclude an effective model for previewing the effects before applying refactorings. A computer-aided refactoring environment (CARE) is developed to supply timely evidences for developers at different stages of a refactoring process. The analysis of refactoring effects is also applied to diagnose undependable execution of batched refactoring plans and to automate test-driven refactoring.

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