The .NET Framework 3.0 enabled developers to build both sequential workflows and state machine workflows. State machine workflows, when designed and implemented correctly, they are just as valuable as sequential workflows. Furthermore, this style of workflow is a good starting point for building human workflows.
In the February issue of MSDN Magazine, Keith Pijanowski covers state machine theory, shows you the design-time experience, and demonstrates the basic activities needed to build a usable state machine with Windows Workflow Foundation.
The code download for this article contains all the workflows, code figures, and code snippets shown in this article. It is designed as a sandbox or test arena for state machine workflows; consequently it will only run one instance of a workflow at a time.