For a long time IT-system maintenance has been reckoned as the largest expense attached to the IT-department, but there has been relatively little research on this subject.
This investigation looks at IT-system maintenance by presenting results from a questionnaire performed in Norwegian organizations. We have looked at how the different organizations perform development and maintenance of their IT-systems. We hope the results can increase the knowledge within this area and improve the organizations ability to perform maintenance in a cost-effective way.
This investigation is the third in a series of such investigations, and that is why we compare our results with [Holgeid 99] and [Krogstie 94].
The share of maintenance-work is significantly larger than the share development-work. The share of maintenance compared to the share development is lower than in [Holgeid 99], but still relatively large compared to earlier investigations. In our investigation the amount of traditional maintenance is almost 66%, when we compare share traditional maintenance to share development.
Work related to development of functionality in IT-systems comes to 39%, and maintenance of the existing functionalities make up the remaining 61%. This is similar to the results in [Holgeid 99], but a big change compared to [Krogstie 94] where functional development was at 56%, and functional maintenance 44%. In our investigation, as in [Holgeid 99], functional maintenance is higher then functional development, while in [Krogstie 94] the opposite was reported.
The share of maintenance looks to have increased compared to earlier investigations, except [Holgeid 99]. Several conditions seem to influence share maintenance, one of them being the complexity of the portfolio. Organizations with a complex portfolio seem to have significantly less maintenance than organizations with less complex portfolios. Intuitively this may look unnatural, but similar features have been reported in earlier investigations (e.g. [Holgeid 99]).
Organizations which do not use pre-defined methods in their development and maintenance have more maintenance than organizations that use pre-defined methods.