将PMI 引入到工作流管理系统经典的安全模型中,建立了一个基于PMI 的工作流管 理系统安全模型。同时将基于角色和任务的访问控制引入到工作流管理系统安全模型的PMI授权策略中,扩展了基于角色的PMI 授权策略。 关键词:角色; 任务; 工作流管理系统; PMI; 授权策略 Abstract: Referring to the classic security model of WFMS (Work Flow Management System), this paper constructs an improved security model of WFMS based on PMI. In the same time, it extends the PMI authorization policies based on T&RBAC (Task and Role Based Access Control). Key words: role; task; WFMS; PMI; Authorization Policy