Metrics
Incident cost
Incident cost is the engineering cost of the breaks that landed in the period. One break is a change undone by a git revert. Its hours are at least 0.5, or 1.0 times the non-merge commits on that break, times the loaded hourly rate. The cost is 0 when nothing broke in the period.
This cost is separate from failure risk cost. An empty period does not remove the assumed failure risk cost. Engineering Overspending is sync tax plus both costs.