Workflow + TAC + Module Grants?

Hi Rik,

I have yet another project that might benefit from your awesome modules... I'm having a bit of a hard time wrapping my head around it though... It may not be a Module Grants question, but based on searches I have done you may be able to point me in the right direction.

I have a content type called "Procedures". Each has a "Department" tag that states for example "Technology", "Curriculum" etc....

I also have Workflow setup with a "Procedure Workflow" with "Drafting", "Pending" and "Approved". Along with this I have 3 roles "Procedure Drafting", "Procedure Pending" and "Procedure Approved".

And as a Cherry on top I have a role per "Department" to control TAC with.

That being said... Here's what I'd like to see happen...

I need anyone of the 3 procedure roles to be able to create a Procedure node... Particularly anyone would has the Procedure Drafting role should be able to so I'd be giving the create procedure permission to that role... Catch is I want only those with a specific Department role be able to create a Procedure with that tag... Simple enough considering I have been able to set up the segregation of terms each user can create a Procedure with using TAC.

At this point the node is in the Drafting Workflow and anyone with the drafting role and the corresponding department role can edit it. If the user only has the "drafting" role however, they can only set the workflow state to Pending for approval... ie not to Approved.

Next the Procedure gets moved to the Pending Workflow state, at which point only those who are part of the Pending role and of course its corresponding department role can make changes... they are also the only ones who can move the node to it's last state, Approved. Once Approved only those who are in the Approved Role should be able to revert the procedure back to any other state for editing...

The problem I am having is that the TAC module allows editing to the entire "life cycle" of the node... vs the Workflow module grants access to editing on the content type level across all departments...

I'm wondering if it's Module Grants or Revisioning or maybe even both that I'm missing in order to get this to work properly... I don't generally need the Revisioning module for this project but if it provides the added layer needed I wouldn't be against it...

You've helped me out on major projects before and I really appreciate any light you are able to shed on this.

Thanks!