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.
IfSQ Defect Indicators based on this finding:
SP-4—Module Not Cohesive
Routines which are cohesive are typically easier to modify, easier to fix and contain less errors than routines with diverse tasks.