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Mea Culpa — SharePoint Designer *CAN* Create State Machine Workflows

I’ve recently learned that it’s possible and even fairly easy to create a state machine workflow using SharePoint Designer.  Necessity is the mother of invention and all that good stuff and I had a need this week that looked for an invention.  Coincidentally, I came across this MSDN forum post as well.  My personal experience this week and that "independent confirmation" lends strength to my conviction.  I plan to write about this at greater length with a full blown example, but here’s the gist of it:

  • The approach leverages the fact that a workflow can change a list item, thereby triggering a new workflow.  I’ve normally considered this to be a nuisance and even blogged about using semaphores to handle it.
  • SharePoint allows multiple independent workflows to be active against a specific list item.

To configure it:

  • Design your state machine (i.e., the states and how states transition from one to the next).
  • Implement each state as separate workflow.
  • Configure each of these state workflows to execute in response to any change in the list item.

Each state workflow follows this rough pattern:

  • Upon initialization, determine whether it should really run by inspecting state information in the "current item".  Abort if not.
  • Do the work.
  • Update the "current item" with new state information.  This triggers an update to the current item and fires off all the state workflows.

Aside from the obvious benefit that one can create a declarative state machine workflow, all that state information is terrific for building KPIs and interesting views.

It does have a fairly substantial drawback — standard workflow history tracking is even more useless than normal 🙂  That’s easily remedied, however.  Store all of your audit type information in a custom list.  That’s probably a good idea even for vanilla sequential workflow, but that’s for another blog post 🙂

I call this a "mea culpa" because I have, unfortunately, said more than once on forums and elsewhere that one must use visual studio to create a state machine workflow.  That simply isn’t true.

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4 responses to “Mea Culpa — SharePoint Designer *CAN* Create State Machine Workflows

  1. Mike May 15, 2008 at 5:46 am

    I implemented the state machine using a separate list to hold the state during the state transitions. The main workflow created an item here and set the initial state.  I used a single, separate, workflow to handle all of the states, using an "IF-THEN-ELSEIF" structure (in "Step 1") on the possible states.
     
    For each state, all I needed to do was obtain a response from a user.
     
    My example was a multiple-level sequential approval, where each step (represented by a state) could have various possible successors.  This meant that each user had (potentially) different options made available in a choice menu.  My "Step Two" was also an "IF-THEN-ELSE" structure that considered all of the possible responses (from all stages), and then decided on what the next state should be.  "Step 3" then set that state, and the workflow ended.
     
    This method has the (obvious) advantage of happening within a single (secondary) workflow.  However, the scope of what could be accomplished in this workflow is more limited that one would have with workflows for each state.  I was wondering, however, what sort of performance hit takes place if all of the individual state workflows start up (albeit ending immediately thereafter).
     
    Also, I use a secondary list (with its own workflow) to represent the transition between states as this process might be only part of a larger workflow.  When the main workflow starts the state machine process, it goes into a wait state, and proceeds when the "looping" has termintaed.  I was also contemplating the possibility that my main workflow may well want to change data in the original List Item, and I wanted to avoid having unnecessary "firings" of the state machine workflow.
     
     
     

  2. Paul May 15, 2008 at 6:14 am

    That\’s a really interesting approach puts an exclamation point on the larger point that SPD can create state machine workflows. 
     
    I don\’t know if there are substantial differences performance-wise between what you outline and what I outline.  In my case this week, performance isn\’t an issue because this particular workflow is a long-running affair (16 or more weeks from start to finish) and there are never more than a few dozen active at any time.  If there were a few dozen starting up and running every hour … that would be a different story.  I think that performance and workflow in general is a very hazy subject.
     
    I don\’t know if you run your own blog or not.  If you do, you ought to consider writing about your approach in more detail.  If not, I\’d be more than happy to call you a "guest blogger" and upload your post to my blog.
     
    Thanks for the comment.  It\’s one of the best I\’ve been able to elicit on my blog!
     
    –Paul G
     
     

  3. Sanjeev May 20, 2008 at 8:26 am

    I\’d really like to read the full examples. Hopefully one of you guys can help clarify some nightmares I\’ve been having with my similar process. I\’m at the point where I\’m ready to start from fresh.

  4. Juan Luis June 6, 2008 at 3:53 am

    Hi Paul,
     
    how many states are you dealing with? I only get to have two different active workflows when I go to the workflow settings page?
     
    Best,
     
    Juan.

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