Coastal zone managers in the Netherlands require new dedicated tools for the assessment of the long-term impacts of coastal maintenance policies. The policies need to be evaluated on the impacts on multiple coastal functions in order to be able to optimize the performance of such strategies. This paper provides the technical backgrounds of such a model. A combined approach with a modified Pelnard-Considere (1956) coastline model and an ASMITA model (Stive & Wang, 2003) was used for this purpose.