I'm trying to prevent users to make new revisions if an item isn't going through a change in TC.
Is it possible ? If yes how ? And is it doable both on Unified and RS ?
Thank you in advance,
This may be possible without customisation depending on your business process.
For revise the revising user requires write access to the Item object, and copy access to the ItemRevision (and any copied attachments such as forms, datasets etc).
If you deny write to the Item then your users won't be able to revise.
You could then selectively open up write access to the Item using a workflow acl.
This implies that you have a workflow running at the point in the change where your users revise impacted to solution items, and the workflow needs to be able to attach the items so the acl applies.
If this isn't possible in your process then you may need to add a precondition.
Sorry for my delayed answer,
Could you please explain me a little more how to get to this result with the pre-conditions ?