Robert Westerlund

A developer's blog on code, technology and tools in the Web, .NET and other development areas.


State Machine in WF vNext

About a year and a half ago, I wrote a post regarding the fact that they removed the State Machine when rewriting Workflow Foundation (WF) to create WF4. When listening to one of the PDC 2010 presentations regarding WF vNext, I found out that one of the news for the next version of WF was the State Machine. The other news coming with vNext, directly from the list in the presentation:

  • State Machine
  • C# Expressions
  • Versioning
  • Dynamic Update
  • Enhanced Workflow Designer
  • New Activities
    • Database, SendMail, REST Client, …
  • WCF Workflow Service Improvements
    • ?Security, Contract First
  • Partial Trust

You can see the whole presentation at:

No state machine in WF4

I attended a TechEd pre-conference session today, in which one of the presenters, Zoiner Tejada, said something that surprised me. There will be no state machine workflows in Workflow Foundation in .NET 4.0.

However, we need not despair in its absence. WF in .NET 4.0 contains a hybrid workflow, which lies somewhere between the still existing Sequential Workflow and the late State Machine; the Flowchart.

I had planned on writing a short introduction to the Flowchart, but I found a nice introductory article to the Flowchart workflow and realised that linking to that article might be a better idea since it spares me the job. :)

As a side note, Mr Tejada also hinted that Microsoft might release an out of band release which would contain the State Machine workflow for .NET 4.0, but he was very specific that as of yet, nothing is certain in that regard.