LESSON 64
MAINTENANCE PHASE
The Maintenance Phase is the last phase in system development.
Maintenance refers to the changes in the system by fixing or enhancing its
functionality.
System developers are involved in the Maintenance Phase.
System maintenance involves checking, changing and enhancing to improve its performance.
All systems need to be maintained to take care of new requirements that were not discovered previously.
CORRECTIVE MAINTENANCE
Corrective Maintenance is changing maintenance carried out to repair an error in system design.
This maintenance is used when errors are detected and need to be rectified.
For example, in the School Resource System, you need to add the International Standard Book Number (ISBN) field.
PERFECTIVE MAINTENANCE
Perfective Maintenance is a system maintenance performed to improve a
computer program.
Perfective Maintenance is done when the users require changes in the interfaces.
For example, in the School Resource System, you can modify the layout of the Book Form by changing the font colour, type, size and adding "Book Form" title.
PREVENTIVE MAINTENANCE
Preventive Maintenance is a maintenance aimed at the prevention of future breakdowns and failures.
This maintenance is carried out when there is a possibility or risk of failure while operating.
For example, in the School Resource System, you want to assign a password
before a user accesses the database.
Some users may only be allowed to view data in a particular Table.
Some may only be allowed to add records to a Table while others may be given the right to view and modify information.
The use of passwords thus helps to prevent unauthorised access to confidential information.
Preventive Maintenance needs to be done to avoid possible future problems.
EXTENSION : BACKUP A DATABASE
Backup is a process of making copies of data. To backup a database involves the backup of a whole database system.
The backup can be used to restore the original data to prevent data loss caused by virus or power failure.
Backup of database should be done regularly. In this way, you can still access to your backup if anything goes wrong.
Backups should be done on an external medium with a USB memory stick, external hard drive, CD, DVD or server.
