Research On Exception Handling Of Workflow Systems In Web Services Environments

As the advancement of network technology and the pressure from our government, modern information services infrastructures, such as manufacturing information system, electronic government, electronic commerce and etc., and application systems develop very quickly. And these infrastructures and systems take processes as their core. As an effective tool for business process modeling, management and monitoring, workflow management system has attracted attention from industrial, academic and research domain and has become a hot research topic recently.Web services have been developed very quickly and used broadly in recent years, which brings us up an open and standard business environment. As a result, the market competition becomes more and more intensively. Thus, enterprise business process management system should adapt to these dynamic changing and inter-enterprise's complicated application quickly. Due to dynamic and various business processes, however, it is difficult for workflow to model the changes of a business process. Therefore, it is inevitable that there may happen some exceptions in an application. Although there are many research literatures on exception handling of traditional workflow, there are few researches about that in the new type of workflow system which is based on web services. However, workflow system in web service environments has its outstanding characteristics, such as huge candidate web services, heterogeneous object, dynamic invocation. Thus, it is very important to study exception handling mechanism of workflow in this new environments both theoretically and in practically.We propose a new model of workflow system exception which refers the exception ideas from OOP. Its main characteristics are: 1) it separates processes of exception handling from normal business process, which simplify the main business process and make us focus on the main aspect of our business; 2) It provides an exception handling mechanism for dynamic invocation of web services. 3) It complies with the original workflow model. The proposed model consists of exception-aware, rule-chooser, CBR, exception handling, rule database and exception handling case database (EHDB). The thesis is organized as follows. It first proposes the model and then constructs the architecture. After that the design and implementation of the mechanism is elaborated. At last, the feasibility of the approach proposed is analyzed through a case study.