该文档是借助于当前系统的逻辑模型导出目标系统的逻辑模型，解决整个项目系统的“做什么”的问题。在这里，对于开发技术并没有涉及，而主要是通过建立模型的方式来描述用户的需求，为客户、用户、开发方等不同参与方提供一个交流的渠道。-The document is the current system through the use of the logic model of the logic of the target system to export the model to solve the system of the whole project " what"　question. Here, for the development of technologies and not covered, but mainly through the establishment of the model to describe the way the needs of users, customers, users, developers and other participants to provide a communication channel.