Maintenance

Making changes to the software after it has been handed over to the client, and enters productive use.

Maintenance

Maintenance activitiesThere are 3 categories of maintenance:

Corrective maintenance

Adaptive maintenance

Perfective maintenance

Fixing bugs and removing errors which did not show up in the software development and testing phases.

Corrective maintenance

Changes to the environment in which the software operates means necessary changes to the code

Could be updated operating system, or new hardware

Adaptive maintenance

Responding to user requests for changes in functionality or additional features

Perfective maintenance

Maintenance activities

New applications

As users gain experience of a new application, they will begin to see potential improvements and features.

Staff mobility

It is always easier for the original programmer to update the code than someone else. When staff move on, it becomes harder to maintain code unless it is very well documented.

Factors affecting maintenance

Too many versions

It can be difficult to trace changes in code if there have been a number of releases.

Use of version control can help this problem

Factors affecting maintenance

Insufficient documentation

If the design documentation or internal commentary is poor or missing, then maintenance will be affected.

Factors affecting maintenance

Insufficient documentationA good use of variable names and internal commentary:

Factors affecting maintenance

External hardware and software changes

Changes to hardware platforms, or upgrades to operating systems can affect maintenance requirements.

Factors affecting maintenance

The cost of maintenance will obviously vary from one project to another.

It is estimated that between 40% and 70% of the overall software development lifecycle costs are spent on maintenance.

The cost of maintenance