Introducing Windows Workflow Foundation
Windows Workflow Foundation is a core component of the next generation of the .NET Framework, called WinFX. Windows Workflow Foundation is broadly available to all users of Windows running Windows XP, Server 2003, Windows Vista, and the next generation Windows Server release. Some of the key goals of Windows Workflow Foundation technology are to
Provide a singular engine for workflow execution for all applications built on the Windows platform.
Support a wide range of scenarios from a highly people-centric workflow to the highly structured application-centric workflow and a variety of blended rules based on conditional scenarios.
Bring model-driven workflow development to the entire WinFX development community such that every developer who today is familiar with the .NET Framework application can be immediately productive, building workflow-enabled applications without learning a second parallel set of technologies.
Enable reuseable workflow component development through strong extensibility points and ensure both developers and ISVs can deeply embed this technology in their applications.
This is a very bold set of goals and Microsoft is achieving these goals by focusing on the core workflow requirements across many scenarios. Windows Workflow Foundation is primarily an engine and a framework—it is not a fully featured product built for a specific scenario. Indeed, although Windows Workflow Foundation is an incredibly important part of all the scenarios described earlier in this chapter, it is insufficient to complete each of these scenarios. For example, in BPM, workflow is supplemented by many features including publish and subscribe messaging, business activity monitoring, and specific development and management tools. Similarly, document lifecycle management requires information worker–centric user interfaces to manipulate the documents and collaboration centers to share them. Nevertheless, developers and ISV can use Windows Workflow Foundation and build all these scenarios around the technology.
Windows Workflow Foundation takes a unique approach to workflow, which is highly extensible. It does not have an inherent language and instead it executes a set of Microsoft and user-created steps. By taking this engine- and framework-based approach, Windows Workflow Foundation is able to address a broad range of scenarios rather than becoming restricted to a singular niche scenario and provide substantial opportunity for partners and ISVs to build a workflow ecosystem around the technology. The next section details the engine architecture for Windows Workflow Foundation.