引言
對(duì)于系統(tǒng)工程師來(lái)說(shuō),設(shè)計(jì)用例圖是一種極為常見(jiàn)的建?;顒?dòng)。用例圖是一種黑盒視圖,通過(guò)向讀者傳遞一系列的用例以及相關(guān)的參與者,對(duì)系統(tǒng)對(duì)外提供的服務(wù)或系統(tǒng)具備的行為進(jìn)行建模。在詳細(xì)討論SysML的用例圖之前,我們先來(lái)了解一個(gè)非常關(guān)鍵的概念 - 用例。
什么是用例?
用例,英文為 “Use Case”,不同的書(shū)籍或論文資料對(duì)于 “用例” 有不同的定義,本文引用《Writing Effective Use Case》一書(shū)中關(guān)于用例的描述:
A use case captures a contract between the stakeholders of a system about its behavior. The use case describes the system’s behavior under various conditions as it responds to a request from one of the stakeholders, called the primary actor. The primary actor i