Defects Average Lifetime (all priorities)

Purpose

Defects Average Lifetime (all priorities) shows how much time on average a defect spends in a development cycle.

How metric helps

Defects Average Lifetime (all priorities) helps to monitor, analyze and improve a defect processing flow in a project. It's suggested not to keep a defect open for more than 30 days. It may cause a user's satisfaction decrease and an application overall quality and stability.

How metric works

Chart overview

Chart shows a number of days it usually takes for a defect to be fixed - number in the center. Target value is above the chart.

By click on a chart a pop up appears with the following information got from the task tracking system: 

  • Issue ID

  • Type

  • Priority

  • Summary

Calculation

Defects Average Lifetime (all priorities) = (number of days defects were in not "Done" status/ number of all defects).

RAG thresholds:  Red - metric value > 30; Green - metric value = < 30. 

Assumptions

1 Calculation considers closed items within the last 90 days.

2 Defect is an item of a type set in Project Configuration > Data Sources > Task Tracking System> Scope Management > Definition of Work Buckets > Defects

3 "Done" status is a status from "Done" bucket in Project Settings>Data Sources>Task Tracking System>Workflows.

4 Invalid defects are excluded from the calculation. Invalid defect is that conforms to Project Settings ->Data Sources ->Task Tracking System ->Quality Management ->Criteria for invalid defects. 

Data Source

Data for the metric can be collected from a task tracking system (Jira, TFS, Rally, etc.).

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