TDWF: A Workflow Model Based on Cooperation of Web Services

Currently technologies of Web services have greatly developed and provided a new application platform for CSCW. For a business process across enterprises, cooperation of multiple Web services is usually required to achieve the final goal. However, most current Web services choreography proposals, such as BPEL4WS or WSCI, only provide a fixed execution flow, lacking of flexibility and adaptability. In this paper, we propose a flexible workflow model TDWF, which can specify the execution process of Web services according to task dependency information, so that the Web services can be composed dynamically. We also put forward an algorithm to verify the correctness of the composition process. Besides, the proposed compensation mechanism of workflow could properly satisfy the requirements of end users