第03章 软件需求获取.ppt

3.3 用例与功能需求 Use cases?can not replace functional requirements, they are different view of the product, one is from user, the other is from developers More information is needed to derive functional requirements used for next phase – software design How to document requirements Use Cases Only Use Cases and SRS SRS Only Which one should you choose? The most fitted one is the best one! 避免用例陷阱 Too many use cases?? Including user interface design in the use cases?? Including data definitions in the use cases? Use cases that users dont understand Excessive use of includes and extends relationships 需求获取中的模糊点 Collecting input from too few representatives, customers or users Project scope is improperly defined, being either too large or too small Miss leaded by the definition: What and How. The grey area is also very important No confidence whether you have collected sufficient information 完成需求获取的标志 尽管实际工作中没有结束条件,但如果出现下述信号，则表明你已基本完成需求获取: 用户总是按其重要性的顺序来确定使用实例的，如果用户不能想出更多的使用实例 如果用户开始讨论已讨论过的使用实例或需求 如果用户提出新的使用实例，但却可以从其它使用实例导出或是其它使用实例的可选过程 如果所提出的新的需求是针对将来产品的而不是现在讨论的特定产品 如果用户新提及的需求都属于低优先级的,没有更重要的需求 课程项目 课后作业 目的： Establish Vision and Scope Document 建立项目视图和范围文档 Template 模板 Total solution Location Determination Technologies Cell ID A/TOA E-OTD A-GPS Network Firmware Applications Location Users Location Server Location Client Location Request Location Response User Interface 项目范围 Based on Vision and Scope DocumentEstablishing Use Case Diagram Identify actors Identify use cases Roughly specify flows of events in each use case Don’t forget preconditions and post conditions for each use case Time: 20 mins Brainstorming!!! Based on Vision and Scope DocumentEstablish Use Case Diagram 以组为单位简述所确定的use cases 每组一次描述一个use case 课后基于your product vision and scope完善所有use cases, they will be the basis for deriving the requirements * 对客户输入进行分类 客户或用户提供的需求信息往往是零散的、缺乏组织的。需求分析者必须把这些零散的信息按某种规则分成不同类型以便最终形成组织良好的需求文档。 对客户输入进行分类 业务需求 Business (op) requirements 描述客户开发部门可以从产品中得到的资金、市场和业务利润方面的需求信息最有可