When I'm asked who, why, how and when a record was changed, I have a limited way of knowing this. It is incredibly helpful to manage data comprehensively when you can see who updated records and how.  I used to have an auditing tool which showed changes made: i.e. <deleted> Primary Phone <deleted> 303-111-1111 and <added> Primary phone <added> 303-555-555.  This showed me who removed a phone number and added a new one.  This ability to audit is helpful in many ways beyond seeing what changes were made, when and by who but ultimately allows a better ability to monitor data integrity. In advancement, its important to know how and in which ways the database is being enhanced.