单项练习之用例图 某零食厂家使用购物预约管理系统。 预约管理人责任客户预约商品的登录、浏览、更改和删除。 员工查看已预约的商品，确定当天的工作。 该预约管理系统与客户信息管理系统连动，在进行预约商品登录的同时可以浏览预约订货客户的信息。客户、管理员和员工进行操作时要先登录。-Individual practice use case diagram　some snacks manufacturers use shopping reservation management system. Appointment management liability customers booking commodity login, browse, change and delete. The employees view the booking of goods, the day s work. The reservation management system and customer information management system linkage, in reserved commodity login can be browsed at the same time booking orders customer information. Customer, administrators and staff the operation to login.