Business cases are in a constant state of refinement up to the moment that production scale deployment begins. Early business cases build the arguments that project implementation can produce value for customers. Evolved business cases reflect backup and evidence requirements of regulatory bodies, and calibration to the final systems actually chosen for implementation. Typically, after deployment begins, the business case is a tool that provides metrics against which to evaluate the success of the deployment effort. The final version of the business case needs to withstand the potential of a post-project audit from the regulators. Our business cases are rooted in 15 years of day-to-day project implementation support, which provides opportunities to validate cost and benefit assumptions in the real world. We have completed start-to-finish project monitoring and business case validation across North America.