When scoping a process improvement project I use this checklist to talk the customer though the various elements that might have to undergo change.
What's does he/she want changed in the IT department? Will anything in the user organization have to change as well? Do the information systems also need to be changed, for instance the procedures or the documentation? Are we just talking about making process descriptions for (quality) managers or are the practitioners actually going to change their way of working, therefore entailing change of behavior? In which case we're also talking about changing habits and 'attachments'. Is the IT department introducing new services or repositioning itself, for instance as a business partner? Is the headcount going to change? Their knowledge and skills? Roles and responsibilities? Tooling?
I strongly recommend using something like this so that you can start with a decent scoping. You'll probably run into scope change along the way but at least you've got a frame of reference to support the revision.