Corrective, adaptive, perfective, and preventive maintenance are the four forms of maintenance.
• Corrective maintenance focuses on resolving issues that arise when the programme is in
operation.
• Adaptive maintenance is concerned with the changes made to the software in order to
make it adaptable to new environments, such as running it on a new operating system.
• The term "perfective maintenance" refers to the changes in the software that occur as a
result of adding new features.
• Preventive maintenance entails making adjustments to avoid mistakes from occurring.
The following graph shows the distribution of maintenance types by type and percentage of
time spent.
∴ Hence the correct answer is Perfective maintenance
