Steering the maintenance costs

Maintenance is a natural and necessary part of the system life cycle and its costs. It is important to control where time and money are spent and what kind of maintenance is performed. For this purpose it is necessary to be able to measure both maintenance, the efforts and costs, and the quality factor maintainability. Such measuring facilitates planning and steering the maintenance work in information systems developing organizations. We present a proposal for a study of a model for measuring software quality. We combine structure, readability, size, numbers of errors and complexity metrics and some process attribute metrics to measure maintainability. The collected values are stored in a metric database, from where periodic reports are written. The reports include graphical presentations of values measured and a ranking of the “top ten” worst modules in a system of the application portfolio. Availability to measurements offers means for the organization to distribute their information systems resources to more profitable objects and to be in control of the maintenance costs, i.e. coordination and reuse of the newly found resources.