What is EVR in software quality?
EVR, or Escape Velocity Rate, explains whether defects are entering a backlog faster than a team can resolve them.
Direct answer
EVR measures whether defect inflow is exceeding defect resolution capacity. When EVR rises above a healthy range, backlog instability can accelerate and recovery becomes more expensive.
The core idea
A project can look active and productive while still becoming less stable. EVR helps separate motion from control by comparing the pace of defect arrival against the team’s ability to close defects.
When inflow exceeds resolution for too long, quality risk compounds. That is why EVR is useful as an early warning signal rather than a post-release metric.
How teams interpret EVR
A healthy EVR suggests defect resolution capacity is keeping pace. A warning state suggests backlog pressure is growing. A critical state suggests the project may need corrective action.
Corrective actions may include retargeting testing, adding focused capacity, adjusting scope, changing dates, or addressing high-risk components first.
How STAR uses EVR
STAR uses EVR alongside defect prediction and backlog forecasting so teams can see not only how many defects may remain, but also whether the project has enough resolution velocity to stabilize.
That makes EVR useful for sprint reviews, release readiness meetings, executive summaries, and pilot evaluations.
Frequently asked questions
Is EVR just the number of open defects?
No. Open defects are a backlog count. EVR focuses on the rate relationship between defects entering and leaving the backlog.
Can EVR be used before release?
Yes. EVR is most useful before release because it can warn teams that instability is increasing while there is still time to act.
Does a high EVR always mean delay the release?
Not always. It means the team should investigate the cause and evaluate corrective actions before release risk becomes harder to manage.