Once a system has been installed and fully operational then the task of system maintenance begins. The maintenance programming term involves keeping the software operational that is undertaking preventive measures to keep computer program running, monitoring the systems operations, fixing problems if any and modifying programs in response to user requirements.
Types of maintenance:
I. Corrective maintenance:
It is performed to correct any errors in newly implemented system.
The errors that can occur in the system –
i.) Logical error (Program logic error)
ii.) System error (hardware problem like disk crash, memory overflow etc.)
iii.) Operational error- It occurs due to inappropriate computer schedules.
· Improper backup of computer files.
· Failure to change printer ribbon.
iv.) User error - It occurs due to deficiency of user training.
The maintenance programmers repair such errors by redesigning the modules in the implemented software system.
II. Adaptive maintenance:
It performs to cope up with the changing environment of the market and organisation. It is performed with a view to keeping the software up to date. This is because, as internal and external business condition changes the data processing requirement also changes. It begins with a request for service from users. Then the request is approved by committee. Then maintenance programmer start work for new requirements.
III. Perfective maintenance:
It is performed to further improve the efficiency of working system. Modifying data structure, baking records, eliminating temporary work files etc are some methods of improving overall system performance.
Some ways to improve efficiency are –
i.) Improving loops and calls to external procedures.
ii.) Improving the evolution of algebraic expressions.
iii.) Modifying expensive parts of the system.