Is it just the top level file that they are changing, not the referenced parts? You could try changing their permissions within their settings to tick the box as below.
This way when they are changing the state of the file it won't change any of the referenced files unless you manually select them.
Yes, I have that option unchecked as its just too dangerous otherwise. BUT, I have taught the users how to use <Ctrl-A> to select all their WIP when moving it along the workflow. Its at that point that Designer's are getting caught with others WIP.
I could add customizations to compare the user that placed the file into ENG Design, and prompt when a different user is attempting to place into ENG Review. That would be fairly easy and effective. Unless of course there is an even simpler solution.
PDM has an option to disallow the same user changing states twice, but doesn't have the inverse of that.
I meant 'checked' not 'unchecked'.