In this paper the software maintenance process will be looked at in more detail from a control point of view. From this it can be seen that in most situations no proper control mechanisms exist and that even the basic requirements for control are not fulfilled. The remainder of the paper will be devoted towards describing a basic approach that provides a starting point for an organisation trying to get a better grip on this problem. Aspects of this approach are: - a distinction between different kinds of maintenance. - types of goals to be used, - assignment of responsibility on a realistic basis, design of proper measurement tools.