Metrics

Accurately tracking software defects and changes is a challenge for software managers. Most organizations track software defects and changes via a defect or change report. The name and information included on the report varies from organization to organization depending on the organization's software process and project type. For example, one organization may use two reports, one to record defects or problems and another to track changes resulting from defects and enhancements, while others will use one report that has a unique identifier to distinguish the report type. Common names for these reports include Software Problem Report, Trouble Report, Error Report, Bug Report, Software Discrepancy Report, Defect Report, and Software Change Request.

Typical metrics collected from defect information include

Defects classified by severity (see Figure 1).
Defect resolution rate.
Defect arrival rate.
Defects per module.
Defects sorted by phase found.
Number of opened/closed defects.
Number of defects opened/closed since the last report.
Severity of open defects.
Rework by phase.