中文摘要：

万维网服务作文让开发者在面向服务的计算上创造应用程序；它的本国的描述，发现，；通讯能力。当具体作文结构是未知的时，这篇论文主要集中于 QoS。服务作文的一个 QoS 模型基于模糊的指导的图理论被介绍。根据模型的意见，一个递归的算法也为计算这种 QoS 被描述。并且，这个 QoS 模型的可行性；递归的算法被案例研究验证。在他们完成服务以前，建议途径使顾客能得到 QoS 的可能的价值。

英文摘要：

Web service composition lets developers create applications on top of service-oriented computing and its native description, discovery, and communication capabilities. This paper mainly focuses on the QoS when the concrete composition structure is unknown. A QoS model of service composition is presented based on the fuzzy directed graph theory. According to the model, a recursive algorithm is also described for calculating such kind of QoS. And, the feasibility of this QoS model and the recursive algorithm is verified by a case study. The proposed approach enables customers to get a possible value of the QoS before they achieve the service.