WW-FLOW: Web-Based Workflow Management with Runtime Encapsulation

We use the term workflow to describe a business process that is executed and managed automatically by a computer system. The definition usually includes all the tasks, tools, procedures, and organizations involved, as well. A workflow management system (WfMS) is an application that uses a computer representation of the workflow logic to define, manage, and execute the process.1 Consider the workflow process in a collaborative engineering strategy for new product development. It may involve cooperation among design, manufacturing, assembly, testing, quality control, and purchasing departments, and may include both suppliers and customers.2 While some of these functions are performed internally, others are carried out by external organizations that might, for example, design specialized components or develop numeric controller machine codes for computer-aided manufacturing work. Not only is such a workflow process complex, but it is also subject to change due to interim results—prototype test and engineering change request processes, for instance. Moreover, when subprocesses for developing component parts proceed in parallel, new requirements can be introduced along the way. Interoperable WfMSs would enable these organizations to cooperate more effectively by readily sharing information and keeping pace with each other throughout the development process. To this end, we identify two main requirements for a WfMS: modular design/execution and Internet compliance. To support modularity, we have adopted an IDEF0-like nested modeling technique to model the workflow processes.3 This method, which we call nested process modeling, allows the process manager to break a complex business process into several subprocesses and provide a structure for hierarchically arranging them. If the WfMS is also fully compliant to Internet protocols, users can have ready access to the system from any location. Moreover, maintenance is straightforward in a Web-based system, and client programs can be easily updated because they need not be installed for each user. Our Web-based workflow management system, WW-flow, was designed to manage complex business processes in a dis-