Building Evolutionary Architectures

Make Sure New Really Replaces Old

PenultimateWidgets legacy accounting system grew over many years, with arcane business rules scattered in many places--no one really understands how everything works anymore. They have been working for several years on replacing the accounting system, but worry that the new system cannot replicate the byzantine business rules that their clients have come to depend upon.

• Categories: holistic, triggered
• Requirements:
• make sure all accounting transactions for invoicing, discounting, and incentives show parity in results across the old and new system
• Additional Context:
• the legacy accounting system has a few spotty unit tests but no good coverage and no other testing. The unit test that exist are pootly maintained and unreliable.