Research Of Servoce Composition Based On Workflow Template

The adaption of information system has accelerated the process of enterprise information and promoted the production efficiency. Meanwhile, there occur some relevant problems such as how to rapidly adapt to the business requirements change, where people are getting more focused on. With the global economic competition getting fiercer, enterprises have to make continuous progress under such environment. They must give a quick and flexible response to customers'requirements, the market opportunity and outer environment. On the other hand, the flexibility and scalability of information system also needs to be promoted by utilizing existed resources and services, then to positively or passively remodel business processes according to market change. Therefore, currently the most important problem in the research field of information system is how to make use of domain experts'experience and encapsulate existing services to compose"bigger services", thus making rapid response to business requirements change and add value to enterprises.This paper combine the knowledge of flexible workflow and web services composition methods to study on the adaptive ability of information system while business logic gets changed. The main idea is to define and encapsulate business process as a workflow template, which in design time has been specified uniform interfaces and will be bound to a relevant service in run time. When business logic gets changed, the templates can be bound to a new service and replace the former one.The main research work includes:(1) To propose a framework for service composition model based on workflow template Based on this framework, business modelers can search for a template match according to users'requirements in service level and the expectancy in coverage and redundancy of a template. (2) To research on strategies in service generationWhen business process gets changed, we must make relevant adjustments such as add, delete, change or merge an activity node. We adopt concepts of inheritance and polymorphism in object-oriented fields into our web services and put forward a service generation method to accomplish the response strategy of workflow template dealing with process changes.(3) To research on the construction of template lib and matching algorithmThe workflow template encapsulates the knowledge and experience of domain experts. Since template lib construction is the premise of template match, we have to define template in a uniform way. In order to simplify the index and management of templates, we classified our templates in usage perspective, and give our matching algorithm accordingly.(4) To design and realize a service composition prototype system base on workflow template. We adapt our service generation methods into our system and verify the usability and effectiveness of our theory through a specific case scenario.Business logic is defined and encapsulated as workflow template. While business logic gets changed, the only thing we should do is to make relevant adjustments to our template, and then our information system can rapidly make response to the change and meet new requirements. It greatly promotes the flexibility of information system in responding to changes. Our method not only decreases the cost arising from business logic change, but also improves the competitiveness of enterprises to a large extent.