
SOFTWARE MAINTENANCE AND PROJECT MANAGEMENT 203
Major aspects
Maintain control over the system’s day-to-day functions
Maintain control over system modification
Perfect existing acceptable functions
Prevent system performance from degrading to unacceptable levels
9.7 CATEGORIES OF MAINTENANCE
Maintenance may be classified into the four categories as follows:
Corrective - r
eactive modifications to correct discovered problems.
Adaptive - modifications to keep it usable in a changed or changing
envir
onment.
Perfective - impr
ove performance or maintainability.
Preventive - modifications to detect and corr ...