中文摘要：

在Web服务无回溯反向链动态框架基础上,提出一个较小执行代价的反向链动态合成方法.该算法根据用户的输入、输出和Web服务的执行代价,在合成过程中的每一步都找到执行代价最小的Web服务,从而动态生成一个执行代价较小的合成方案.该合成方案考虑了Web服务的合成效率和执行代价,特别适合于对两者都有要求的应用领域.

英文摘要：

Based on non-backtrace backward chaining Web Services dynamic composition framework,this paper proposes a backward chaining dynamic composition method to lower the execution price.In order to generate this synthesis program dynamically,the Web Service with minimal execution price is found in each step of the composition course of the algorithm based on user input/output and the execution price of Web Service.The composition approach takes into account the efficiency and execution price,so it is especially suitable for users who have requirements on the both.