Metrics
Failure risk cost
Failure risk cost is the cost assumed from how often a finished change breaks something unrelated, and from what one break costs in engineering hours. It is this quarter's finished changes times that rate times the cost of one break. The cost is assumed even when nothing broke, the same idea as an insurance premium.
Until 20 shipped changes exist, the rate is 0.15 and one break is 0.5 engineering hours. From 20 shipped changes on, the rate is the share of the last 30 shipped changes that a git revert shows had broken something. A measured rate of 0 means this cost is 0. Business impact is not counted.