AbstractSoftware maintenance is necessitated to a large extent by changing user requirements. However, the relationship between the user requirements and the implemented software system is not made explicit in current development approaches, making the mapping of changing requirements to corresponding maintenance activities difficult. The teleological approach advocates the construction of a model which links the components of a software system to the concepts of the application domain which they implement, i.e to user requirements. Subsequently, the teleological model is used for simulating the actual maintenance activities, as they are triggered by the changing requirements, and for identifying their nature and estimating their cost.