What are the types of software maintenance in use?

The key task in the maintenance phase is to make the system last and meet the needs of the users through a variety of necessary maintenance activities.

There are usually four types of maintenance activities: corrective maintenance, that is, diagnosing and correcting software errors found during use; adaptive maintenance, that is, modifying the software to adapt to changes in the environment; perfective maintenance, that is, according to the user's requirements to improve or expand the software so that it is more perfect; preventive maintenance, that is, modifying the software to prepare in advance for future maintenance activities.

Although there is no further division of the maintenance phase into smaller phases, virtually every maintenance activity should go through a series of steps such as making a maintenance request (or reporting a problem), analyzing the maintenance request, proposing a maintenance request, proposing a maintenance plan, approving the maintenance plan, determining the maintenance plan, modifying the software design, modifying the program, testing the program, reviewing the acceptance, etc., and therefore essentially undergoes the So it's essentially going through the whole process of defining and developing software that has been compressed and simplified.