Glossary
Rework cost
The cost of redoing work that was built on something that later changed.
Rework cost is what it costs to redo work that was correct when it was built but is wrong now, because something it depended on changed.
For a change to a business definition, rework cost can be calculated from delivery data an organisation already holds: the story points on affected work items, the day rate of the roles that do the work, and a multiplier for how far each item had progressed. A ticket not yet started costs little to adjust. One already released costs much more.
Calculated, not estimated
A rework cost figure is only persuasive if it can be checked. That means plain arithmetic over known inputs, with each total traceable to the work items behind it, and missing estimates shown as gaps rather than counted as zero.
We describe the full method in how we calculate the rework cost of a definition change.