中文摘要：

为提高Web服务组合的运行效率，提出了基于有色Petri网的Web服务组合网系统概念，用于Web服务组合的建模和性能分析．以电子资源跨库查询过程为实例，构建实例的理想模型和缓存限制模型．模型支持Web服务组合协调节点间的网络延迟、数据依赖、控制依赖等因素．基于CPN Tools仿真平台，验证了模型的正确性，并在仿真实验中监测了查询延迟、查询成功率、缓存占用率等指标．结果表明，实施缓存限制策略前后，分布式模型比集中式模型均有更好的性能．

英文摘要：

Inorder to improve the execution performance of Web Service Composition, the concept of Web service composition net system based on Colored Petri net is proposed to model and analyze the execution of Web service composition. In the use case of electronic resource cross- liberary searching system, the network delay, data dependence and control dependence between nodes were included in the expected models and the buffer-restricted models. By means of the CPN tools, a powerful simulation platform, the correctness of the above models was verified, and the query delay, successful query ratio, the buffer occupancy rate were mornitored. Simulation result showed that the distributed model was more efficient than the central model no matter it worked under buffer-restricted policy or not.