I am wondering, very generally, about the feasibility of a WF solution in an application, where the business owners want extensive reporting capabilities on application state and data.
The main issue that I see is that WF tends to hide data, such as a recipient list, that is serialized inside the workflow instances, so it can't be reported on, in a way I'm aware of.
On the other hand, if the instance data is written out to an external resource such as a sql table, then haven't you just given up your ability to change that part of the workflow at will (taking away a major selling point for WF)?
In WF for .Net 3.5, I understand the SqlTrackingService can provide raw data about Workflow instance events, Activity events, and User events. But, I wonder about the scalability of logging a lot of instance data, in the activities, to User events. Also the schema I see that the SqlTrackingService uses looks like it would be hard to maintain a reporting solution on, especially if there are updates to the workflow over time. Am I wrong here?
So, has anyone out there successfully used WF when reporting was a major concern? If so, I'd like to hear about how it was done, if WF was isolated to only certain parts of the app (having data not applicable for reporting), and so on…
Perhaps, this is just a question about reporting in a BPM solution in general, as well…
EDIT:
I've accepted Maurice's answer because he took the time to answer it, but I'm still interested in any other opinions on this!
Best Answer
Using the SqlTrackingService in combination with tracking profiles is quite performant, specially when you enable transactional logging. Basically you want to use the tracking profile to only track events you are really interested in. You can also tell it to extract and log specific pieces of user data.
The main way to retrieve the data is not through SQL, although that is possible and for some queries like give all workflows executing a specific activity, but the SqlTrackingQuery class. This will also deserialize the additional user data.