Recently I have seen a lot more requirements for traceability of calculations for users. i.e. easy abiliy to understand how a value was calculated. This is coming up as a 'critical' requirement in functional requirements quite often.
I know we have the trace values function, however this is not very user friendly, especially for end users who don't know the business rules behind. My idea is to improve this function with a user friendly UI that shows the business rule in a more understandable way, including the source values so that from the front end the user can easily see what's happened.