Our process is a rather convoluted and I am having trouble incorporating it into EPDM. We have several types of projects dependent on the type of product and the work being requested. The way our process works files might be created under a "F23 - Product Extensions", a "F3 - New Project Request", a "F31 Engineering Change Requests" or a "F38 Engineering Work Requests". Each project gets a specific project number. (ex. F23-0376 or F31-0863). Different projects types have their own path through the design and approval process.
Also, revisions can occur under any of these project types. For example, even though F31 is our ECR process files can be revised during an F23 project. They are considered part of that project and a separate F31 project is not created for the revisions.
Ultimately, my goal is to have searches that would find all files that have been affected by a particular project and find all projects that have affected a particular file. I would rather not use "Paste as reference" as it depends on human input.
Without knowing all of the particulars, it sounds like you should consider having different workflows for your different project types. Each would be configured for the applicable process including revisions. You could search for files in a particular workflow state as well.