大家好，欢迎来到IT知识分享网。
Requirements Level Classification（需求的分类）
To deal with the diversity in requirements types, Sommerville (2005) suggests
organizing them into three levels of abstraction:
-
User requirements
-
System requirements
-
Software design specifications
User requirements（用户需求） are abstract statements written in natural language with
accompanying informal diagrams. They specify what services (user functionality)
the system is expected to provide and any constraints. In many situations user stories
can play the role of user requirements.
System requirements（系统需求） are detailed descriptions of the services and constraints.
System requirements are sometimes referred to as functional specification or technical
annex. These requirements are derived from analysis of the user requirements.
They act as a contract between client and contractor, so they should be
structured and precise. Use cases can play the role of system requirements in
many situations.
Software design specifications（软件需求） emerge from the analysis and design
documentation used as the basis for implementation by developers. The software
specification is essentially derived directly from analysis of the system specification.
The software requirements specification document (SRS) is the “contractual” document
that we generally refer to when we speak of a “software” or “system” requirements
specification.In the case of a hybrid hardware/software system,（考虑软件和硬件系统） the SRS would include both detailed design elements for the software as well as hardware
(e.g., schematic diagrams and logic diagrams). In the case of a purely mechanical
system, design drawings take the place of the SRS.
要求等级分类（需求的分类）
为了应对在规定类型的多样性，萨默维尔（2005）建议
它们组织成三个层次的抽象：
用户要求
系统要求
软件设计规范
用户要求（用户需求）是抽象的语句写在自然语言与
伴随非正式图。他们指定哪些服务（用户功能）
该系统预计将提供与任何约束。在许多情况下，用户故事
可以播放用户需求的作用。
系统要求（系统需求）是服务和约束的详细说明。
系统的要求，有时被称为功能规范或技术
附件。这些要求都源于的用户需求的分析。
他们作为业主和承包商之间的合同，所以他们应该是
结构化的和精确的。用例可以发挥系统需求的作用
许多情况下。
软件设计规范（软件需求）出现从分析和设计
作为基础，实施开发文档。该软件
说明书中基本上直接从系统规范的分析而得。
软件需求规格文件（SRS）是“契约”的文件
我们一般指的是，当我们谈论“软件”或“系统”的要求
specification.In混合的硬件/软件系统的情况下，（考虑软件和硬件系统）将SRS将包括用于软件既详细设计元素以及硬件
（例如，原理图和逻辑图）。在一个纯粹的机械的情况下
系统，设计图纸取SRS的地方。
免责声明：本站所有文章内容,图片，视频等均是来源于用户投稿和互联网及文摘转载整编而成，不代表本站观点，不承担相关法律责任。其著作权各归其原作者或其出版社所有。如发现本站有涉嫌抄袭侵权/违法违规的内容,侵犯到您的权益，请在线联系站长,一经查实,本站将立刻删除。 本文来自网络,若有侵权，请联系删除，如若转载，请注明出处：https://yundeesoft.com/13656.html
