Web環境下需求規格再利用系統之設計

Abstract

軟體再利用的成效與元件庫中元件數量及所涵蓋應用領域多寡有緊密關係。在企業內部再利用環境中，常有軟體元件數量及涵蓋領域不夠多之缺憾。在Internet/WWW環境下，再利用者應可再利用全世界各式各樣不同領域的軟體元件庫中的軟體元件，以提升其軟體生產力。軟體再利用的層次分為需求規格、設計以及程式碼再利用，若能越早再利用現成的軟體產物，所獲得的效益越大。然而，目前在Web環境進行需求規格再利用的研究成果並不多見，本研究旨在探討如何在Web環境下進行需求規格再利用。在Web環境下進行需求規格再利用與傳統的需求規格再利用環境之不同處有：(1)再利用的應用領域不限於以往熟悉的應用領域、(2)元件格式不固定、及(3)需付費才可取得完整元件內容。為提供一良好Web上進行需求規格再利用的環境，本研究提出一以仲介者（Broker）為基礎之需求規格再利用系統，負責收集整理Web上可被再利用之需求規格元件資訊，並提供交易的平台。 依據一般需求分析的流程及所產生的軟體產物，我們將應用再利用技術的時機分成應用領域知識再利用、需求再利用及規格再利用。在Web環境下，由於軟體發展者不易再利用不同格式的元件，且元件格式不固定造成Broker系統在分類及管理元件上的困難，因此我們選擇以業界最常用之Unified Process及UML制定之需求規格作為研究對象，並針對三個進行再利用的時機分別找出被再利用的對象，包括有：(1)系統之Business Model、Domain Model及發展時所參考之資料、(2)系統之服務需求及其相關之use case集合、及(3)依據需求所分析出之系統的analysis model或其中之analysis package。由於這些被再利用的對象其智慧財產屬於原開發者所有，Broker並無法獲得完整的需求規格元件內容，因此我們提出以摘要方式記錄被再利用的需求規格元件的資訊，並以此摘要資訊提供給使用者以作為購買元件時的參考。此外，為了方便使用者之瀏覽與搜尋，對於儲存於Broker系統中之需求規格元件資訊，我們除依其應用領域進行分類外，另外並設計了一搜尋元件的機制及工具，可讓使用者很容易找到其想要的需求規格元件。

The number of reusable components and the extent of domain coverage in a reusable components repository dominate the success of software reuse technology. Traditionally, the organizational reuse often suffers from the insufficiency of software components and domain coverage. Within the Internet/WWW environment, the reuser may reuse the software components from repositories of various domains from vast Internet/WWW spectrum and the software productivity is promoted substantially. Software reuse can be initiated at the phase of requirement & specification, design and code reuse. The earlier to initiate reuse, the better benefit is obtained. However, there is little research of reusing requirement & specification on Internet/WWW currently. The main purpose of our research is to propose the reuse of requirement & specification on Internet/WWW, denoted as wide-area reuse. There exist several differences between wide-area reuse and traditional organizational reuse of requirement & specification: (1) The reuse domain is not limited to the familiar ones; (2) the format of reusable requirement & specification component is not fixed; (3) it is not free to access the reusable artifacts. To facilitate the wide area reuse of requirement & specification, we introduce a broker-based requirement & specification reuse system. It is responsible for collecting the information about reusable requirement & specification components and providing a trading environment for reusers and component vendors. According to the process and artifacts of requirement analysis, we classify the reuse of requirements and specification into three types: domain knowledge reuse, requirement reuse and specification reuse. Within Internet/WWW environment, the components formats varies, confronting the reuses to reuse them and the vendors to classify and manage them. Thus, we focus on the requirements and specification following the Unified Process and UML that are widely used in industry. Then we classify the potential reuse artifacts in three phase of requirements analysis, i.e., the Business Model and Domain Model of a system and reference documents, the system requirements and related use-case clusters, and the analysis model or one analysis package. Because the vendors own the intellectual property of reusable artifacts, it is impossible for broker to access all their contents. We introduce a mechanism to get abstract information about the reuse components. Then users can understand the components they are interested in via the abstract information. Besides, we also design a classification scheme and a search mechanism for user to browse and search reusable components easily in Broker. We have developed a broker system based on the research result of this thesis. It has been integrated with the reuse of wide-area code component that is previously developed by our laboratory.