关键词: Web服务, SAP系统, 可信计算, 诚信度, 关键路径, 关键服务

Abstract: With the large growth in number of Web services and the demand for registries, there is a growing response time-spending on completing a Web service call of SAP（Systems Applications and Products in data processing） enterprise system, and some of these Web services are untrusted. It seriously hinders the efficiency and quality of service’s request. This paper introduces the trusted computing, namely the concept of integrity. It combines critical path in engineering, proposes a determine algorithm of critical path of a Web service call based on integrity algorithm innovatively. For the Web services that meet the requester’s demand registered in the UDDI（Universal Description, Discovery and Integration）, it uses integrity algorithm to calculate them, excludes part of the Web services of which integrity values are below requester’s expectations; it puts the process of a trusted Web service call abstracted into AOE（Activity On Edge） network diagram represented by weighted directed acyclic graph, finds a critical path of a Web service call in the graph by means of critical path determine algorithm. Services on the critical path are all critical services. By using the SAP system client buffer management, business agents and other design patterns, it reduces the call time of critical services to improve the efficiency of the critical path, shortens service call response cycle, further improves the overall efficiency and quality of service calls. It develops the practical system to verify the feasibility and effectiveness of the algorithm. The system has been run in a group. It reduces enterprise’s operating costs, improves work efficiency, and is praised by the user satisfaction.

Key words: Web service, Systems Applications and Products in data processing（SAP） system, trusted computing, integrity, critical path, critical service