需求分析再利用系統之設計

Abstract

軟體再利用可區分為需求規格再利用、設計再利用和程式碼再利用三個層 次，其中尤以需求規格再利用能得到最大的效益。需求分析階段的再利用 可分為：領域知識再利用(Application knowledge reuse)及規格再利用( Specification reuse)。領域知識再利用是指分析師可依據新系統所屬領 域及性質，尋找類似或相同領域下的系統需求分析文件，參考其客戶訪談 結果、系統切割策略、系統服務需求描述等需求分析相關資訊，以加速分 析師制定新系統服務需求之制定過程。規格再利用則是採用組合式再利用 程序，以子子系統為單位，依據各子子系統之服務需求，搜尋合適的系統 規格元件以資利用。當所有子子系統規格定義完成，在由下往上組合成子 系統及系統規格的過程中，分析師亦可再利用現存的系統規格，參考其組 成單元間的交互關係，加速規格之組合。FDOOA軟體需求規格再利用的單 元主要有系統規格單元含子系統及子子系統）、功能規格單元（含系統功 能及子功能）以及類別規格單元。其再利用程序之主要步驟有：(1）領域 知識再利用（2）規格再利用（3）組合再利用。本論文所提的FDOOA需求 規格再利用程序及關鍵技術設計具有下列特色及優點： (1) 加速分析師 制定新軟體之服務需求及規格撰寫。 (2) 以子系統為再利用單位，依據 子系統的服務需求定義轉換特徵搜尋合適的子系統規格以茲再利用。一旦 分析師再利用子系統規格，則其之所包含之功能及類別規格也可一併被再 利用，使得再利用之效益更加顯著。 (3) 利用領域性質及轉換特徵所組 成的層次性(layer)分類架構，可提昇規格元件搜尋的速度及精準度。 There are three constitutes in software reuse, including specification reuse, design reuse, and code reuse. The specification reuse has better benefit. The reuse of specification analysis stages are application knowledge reuse and specification reuse. Application knowledge reuse is mean that the analyst can use the domain and properties of new system to search the specification analysis documents of the system in same or similar domain. Analyst can refer the results of the interview with user, system decomposition technique, descriptions of the system service requirements, to speed up the processes of identified the new system service requirements. Specification reuse is based on composed reuse process, impose the service requirements of the subsystem, to search the similar system specification component for reuse. When all the subsystem are identified completely, analyst can reuse the system specifications, refer the interrelationship of components, to speed up the composition of specification, in the process of composed the subsystem and system specification.The components of FDOOA software requirement specification reuse include system specification components (including subsystem, sub-subsystem), function specification components(including system function, subfunction) and class specification components. The major stages of the reuse are: (1) domain knowledge reuse (2) specification reuse (3) composed reuse.The process of the FDOOA requirement specification reuse and critical technique design in this thesis have some qualities and advantages:(1) It can help analyst to identify the service requirements of new software system and write the specifications quickly.(2) The reuse component is subsystem. Use the service requirements to identify the transformation characteristics, and use these transformation characteristics to search the suitable subsystem specifications for reuse. When analyst reuse the subsystem specifications, its corresponding function and class specifications can be reused. (3) It can speed up the searching specification components and accuracy by using the layered classification of domain property and transformation characteristics.