业务流程驱动的半自动语义Web服务组合方法研究及应用

Process-driven Method of Semi-automatic Semantic Web Service Composition and its Application

随着Web服务数量的不断增多,如何利用Web服务组建松散耦合的应用系统以满足不断变化的业务需求,成为一个研究热点。传统的业务流程驱动的服务组合通常需要预定义组合流程,当业务流程改变时则需重新定义流程,因此不能适应动态业务需求。针对上述问题,提出了一种业务流程驱动的半自动语义Web服务组合方法。该方法在业务流程驱动的服务组合基础上,将局部动态流程用抽象服务描述,当流程执行阶段不存在能满足抽象服务需求的单个服务时,采用自动服务组合方式将抽象服务替换成组合服务,并执行自动组合方法。该方法由于采用了基于回溯树的服务组合方法,并在回溯树中增加语义信息,还通过计算组合流程的QoS来实现组合服务的选取,因此能有效解决因缺乏语义导致查全率低的问题。最后给出了半自动化的服务组合框架,该框架兼顾了可用性与动态性的需求,具有一定的实用价值。

As the number of Web services increases quickly, how to compose Web services into loosely-coupled system to fulfill flexible business requirements becomes a popular research topic. Traditional process-driven based service com- position methods and frameworks predefine the composite process. When the local busines^process changes, the whole composite process must be redefined again which lacks of flexibility. This paper introduced a semi-automatic semantic service composition method. The abstract service is used to describe the local dynamic process and will be automated re- placed by composite service at execution phase when there is no candidate concrete service suitable for the abstract ser- vice. A backward-tree based service composition method was proposed for the replacement of the abstract service and semantic information was applied to improve the recall rate of Web service. Considering the selection of composite processes, the QoS evaluation method was introduced. Based on business process method, this paper proposed a semi-au- tomatic semantic service composition framework. OWL-S technology is used for the description of the dynamic process. Finally, an application of credit evaluation case is shown which presents the availability and flexibility of the framework.