What is the best way to measure how long it takes for a task to be taken after creation? Eg, task is created and a group of users are assigned as candidates. But we want to know for reporting purposes how long it actually takes someone to take the task and start processing it.

I haven't tested it, but thought about using the progress field and then check that in the history, if possible. So when the progress changes from 0 (not started) to 1 (start), you can get an interval. Would setting the priority create history entries that can be used for this purpose?

Still need to figure out how to effectively manage a task that is released again and re-taken by someone else... might have to use some custom event handlers?

Any other suggestions?