There is a new draft specification available for open review, called Task Planning Information Model. You can get it at that link, or if you want to find it later, it has links in the usual places on the main specifications link page.
This is an early draft based on an original proposal and model provided by Bjørn Næss at DIPS (Norway). I have so far worked on it with people from DIPS and Marand, who have provided concrete use cases and technical ideas. It's now in a state where we think it's sufficiently readable to obtain comment from the community, particularly other implementers. Noone has implemented it yet, and we don't see anyone's use cases as more special than others - but obviously we had to start somewhere.
There is some background and requirements in the draft. A recent blog post I made may provide more insight for some. The main point is probably this: we are not trying to solve everything, or even that much of the workflow/process question with this spec, only to add an initial extension to the RM that will solve some identified deficiencies in the openEHR architecture.
Every aspect of the design is up for comment. Reviewers will note that there are various 'TBDs' (To be determined) and ISSUEs marked in the draft; please use these tags when discussion the particular issues so we all know what we are talking about.
Our aim is to get an initial implementable version formally accepted in 4-6 weeks, so please have a look as soon as possible.