When considering the applicability of capability models, and IT industry standards, it is important to understand the nature of application support, and the objectives that a support organization is tasked to achieve. Software maintenance is defined as (IEEE, 1990): “The process of modifying a software system or component after delivery to correct faults, improve performance or other attributes, or adapt to a changed environment”. The four types of maintenance are:
1. Corrective maintenance deals with the repair of faults found.
2. Adaptive maintenance deals with adapting the software to changes in the environment.
3. Perfective maintenance mainly deals with accommodating new or changed user requirements.
4. Preventive maintenance concerns activities aimed at increasing the system’s maintainability.