At program level inhibit the ability to change a job entity

We have had issues where job entities have been changed and this has compromised reporting in WIP and AR.  Star PM has the ability to stop jobs entities from being altered based on privileges.  However these may not be applied correctly and/or admin rights override.  As this area is an integral part of the program it has been requested for this field never to be editable or only editable at different stages based on possible switches.  Two common choices a client may want to edit the job entity is (1) before any time is approved, (2) before a bill is raised.