7. The Software Development Process - Maintenance

7. The Software Development Process - Maintenance

• 1.
  Maintenance
• 2.
  Maintenance Making changes tothe software after it has been handed over to the client, and enters productive use.
• 3.
  Maintenance activities Corrective maintenance Fixingbugs / removing errors Adaptive maintenance Changes to the environment in which the software operates means necessary changes to the code. Could be updated operating system, or new hardware Perfective maintenance Responding to user requests for changes in functionality or additional features
• 4.
  Maintenance activities Associated Maintenance Time Corrective 17% Adaptive 18% Perfective 65%
• 5.
  Factors affecting maintenance Newapplications 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.
• 6.
  Factors affecting maintenance Toomany versions It can be difficult to trace changes in code if there have been a number of releases.
• 7.
  Factors affecting maintenance Insufficientdocumentation If the design documentation or internal commentary is poor or missing, then maintenance will be affected. It is good practice to use internal commentary and descriptive variable names.
• 8.
  Factors affecting maintenance Insufficientdocumentation A good use of variable names and internal commentary:
• 9.
  Factors affecting maintenance Externalhardware and software changes Changes to hardware platforms, or upgrades to operating systems can affect maintenance requirements.
• 10.
  The cost ofmaintenance 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.