Disable approval flow functionality on document in sourcing

Hi

Is some one knows how to disable the approval functionality while cliking on  a document on sourcing project?

-> We have designed a complete guidance (on a template) with specific approval flow in sourcing module and are reporting on it. But users (buyers) can still create additional approval flows... (so difficult to report on it).

So we want to avoid this situation.

Any idea?

Thanks a lot