The idea is that you do any comparison before you move to Prod and that you only implement knowing that the changes you are bringing have been fully tested. You never make changes in Prod, and if you need to roll back you do so be re-importing another release.For example, the first version of solution A is ready to go live, a release is made and then imported into Prod. Some time later, in response to a CR, a modified version of the solution is ready to be implemented. Here there is a choice, 1) create a complete release of the whole solution, or 2) create a partial release of only the changed entities. For 1) if there is any uncertainty which entities have changed, then the 'last changed' date of each entity* should be compared with the last implementation date. If the date precedes the last implementation, then you know the entity has not changed. If there has been a change since the last implementation, then the side-by-side comparison will illustrate the difference, but there should also be documented evidence of why that entity has changed. Any implementation should be governed by a Release Procedure and accompanied by proof of testing sign-off.* Applies only to processes and objects.
