中文摘要：

以城市应急处置业务作为应用背景，提出了一个工作流的分层概念模型和一个与之关联的元数据分层描述规范，在此基础上构建了一个基于元数据导航的、从高层的业务应用到底层的分布、动态资源的逐层绑定的运行机制，基于该机制实现了一个城市应急联动系统IERS（Integrated Emergency Response System）的实验原型．该机制解决了从应急处置业务工作流到底层分布服务和资源的装配问题，增强了应急系统对动态、分布服务环境的支持力度，提高了应急处置业务在执行过程中的自动化水平和自适应性，同时也分解和简化了工作流问题的复杂度．

英文摘要：

Aimed at the emergency response application, this paper puts forward a layered concept model for workflow and a hierarchical descriptive model of metadata, and upon which establishes a mechanism for workflow assembly and execution navigated by the metadata. The mechanism is illustrated by using an application scenario of IERS（Integrated Emergency Response System）. The mechanism described here solves the problem of mapping and binding from emergency tasks to distributed services and physical resources, enhances adaptability of an emergency system to dynamic and distributed environment, improves self-adjustability and stability of the emergency system in the course of deployment and execution, and at the same time decomposes complexity and reduces abstruseness of the problems related with workflow.