If the maintenance time exceeds 24 hours, there may be problems. In order to eliminate faults and errors in system operation, software and hardware maintenance personnel should make necessary modifications and improvements to the system; In order to make the system adapt to the changes of users' environment and meet new requirements, some local updates are needed to the original system, which is called system maintenance.
It is often ignored in the whole system life cycle. People are often keen on system development. When the development work is completed, in most cases, the development team is dissolved or withdrawn, but after the system starts running, there are no suitable system maintenance personnel.