One of the key deliverables from the analysis phase is a Fit/Gap document. CRP allows you to review the business fit of the standard processes configured within Dynamics AX and also gets the feedback on the proposed solutions for Gaps.
You can leverage the business process modeler in Microsoft Lifecycle Services (LCS) for complete business processes. Having this created in LCS means that the overall business process is analyzed, and providing access to the LCS project increases knowledge of the gap.
It is important to remember that this is a FIT gap session and Fit should also be analyzed.
Often at times, you will find gaps listed that aren't really gaps, as the solution can handle the requirement.
Another time to revisit and negotiate items that are causing a lot of customization work and can be avoided.