IfSQ

SP-4—Module Not Cohesive

Defect Indicators: (This information is currently under review and available only to Members and Fellows.)

Risks: (This information is currently under review and available only to Members and Fellows.)

Assessment: (This information is currently under review and available only to Members and Fellows.)

Remedy: (This information is currently under review and available only to Members and Fellows.)

References:

• An Empirical Study of Software Design Practices (David N. Card, Victor E. Church, and William W. Agresti), 1986,
• Analyzing Error-Prone System Structure (Richard W. Selby, and Victor R. Basili), 1991.

Research Findings:

• Better to write cohesive routines:
  A study of 450 routines found that 50 percent of highly cohesive programs were fault free, compared to only 18 percent of routines with low cohesion,
• Coupling-to-Cohesion ratio inversely correlated to errors:
  Given a sample of 450 routines, the routines with the highest coupling-to-cohesion ratios had 7 times more errors than those with the lowest ratios,
• High cohesion correlated to low fix cost:
  Routines with low cohesion can cost 20 times more to fix than fixing highly cohesive routines.