Instability Index

Instability Index definition

• It is a code quality metric.
• The instability index measures efferent coupling in relation to total coupling.

Instability Index practice

• The instability index measures efferent coupling in relation to total coupling :
  • Instability Index = Ce / (Ca + Ce) Ce :
    • Efferent Coupling (Ce)
    • Afferent Coupling (Ca)
  • This metric has a range [0,1]
  • A value of 1 means a code component is highly unstable, and a value of 0 means it is highly stable.

Scrum and Metrics

The Scrum framework

More informations for the Scrum PSD certification here.