Maintenance and Support

Maintenance and support will continue for the life of your software system. A significant portion of the system’s life-cycle budget will be consumed by these tasks. In fact, experts estimate that Maintenance can eventually account for 40 to 80% of the total project cost.  The initial planning phase of your project should include a strong focus on the eventual maintenance and support of your system.

What is Maintenance

This is the post-production phase of the software life-cycle.  The different types of maintenance tasks are:

Adaptive  Software modifications required due to environmental changes (eg. system upgrades).

Corrective  Updates that are required to correct or fix problems

Perfective  Modifications that enhance or improve the software performance or functionality or performance (eg. improving mobile compatibility).

Preventative  Correcting potential software problems (eg. implementing protection against more advanced cyber-threats).

What is Support

This is also part of the post-production phase.  It refers to the assistance given to users, categorised as:

User Advice  Training or general advice given to users (not in response to an incident or problem).

Problem Investigation  This determines if a reported incident is a defect or not.  If it is not a defect, it could be a user error caused by lack of documentation or training. If it is an error, it is handed over to the maintenance team for fixing

How the ISBSG can help you:


If you are a Project Manager:

  • Compare key data from your application to similar applications to the ISBSG Data. Establish a benchmark that can be used as a baseline to enable you to plan the Maintenance and Support phase of your project.
  • For implemented projects, the baseline can help you to plan your performance improvement initiatives.
  • Use ISBSG Data for maintenance outsourcing arrangements. It can be  used as a starting point for negotiations about the key performance indicators expected from the outsourcing company.

If you represent an Outsourcing organisation:

  • Use the ISBSG Data to benchmark how competitive and efficient your maintenance and support teams are.
  • The productivity information can be used to adjust your budget,  as new projects come into and leave the maintenance scope.

The ISBSG Maintenance and Support Repository

ISBSG has a Repository of Maintenance and Support data consisting of metrics for more than 1,100 applications.

A wide range of industries are represented (eg. financial, wholesale/retail, banking, communications).  The organisations that have contributed their data, range in size from multinational to small, local companies.  Data has originated from many diverse countries including: India, Australia, Brazil, Finland, USA and Italy.

For more information, see a detailed description of M&S Data Demographics

Find out information about an ISBSG Data Subscription.

The key data that we collect includes:

  • Industry and application type
  • Size of the application
  • Platform Types.
  • Programming language used
  • Effort spent on maintenance activities
  • Effort spent on support activities
  • Number and types of defects found during the maintenance period
  • Average time taken to repair defects
  • Calls to Help Desk
  • Team size

Plan your project’s maintenance and support phase, using ISBSG reports as a reference.

“Analysis of Software Defects Delivered into Production” report analyses the defects that occur within the first 30 days of project implementation.  For example:

application type defects report

“Managing Your M&S Environment” report provides an analysis of defects and time taken to repair defects, for applications of different sizes. Also specified are: Incidents, help desk calls and team size. A detailed breakdown of maintenance and support activities is also discussed.

For more information about maintenance and support reports, see Report Subscriptions.