Enhancement dimension. The activities in the enhancement dimension are even more difficult to define precisely the in terms of results rather than activities. Proactive enhancements (perfective maintenance) are usually initiated by the IT organization themselves to enhance the maintainability of the software and improve their software maintenance effectiveness. This type of change does not directly influence the information system functionality and should therefore be highlighted as such in the SLA. The enhancements required by the customer do have a large impact on his perception of the software section value and therefore can not be easily ignored. It is difficult to predict the number and content of the enhancements that will be requested by the customer during the agreed upon service period. Three approaches on how to deal with this uncertainty and mostly a combination are illustrated here:
