In operational practice, datawarehouses are big corporate databases that are continuously under development. his implies a dynamic increase of the complexity of the data. For controlling this complexity, a conceptual model riven approach is recommended in order to guarantee that the relation to the business environment can be validated at ny moment. To keep maintainable the connection between the conceptual model and the logical/physical aspects of the atawarehouse and related data marts, bridges are needed that can provide the needed model-to-model conversion at ny desired moment. To achieve this, a bridge-toolset was designed and developed which is based on a single point of efinition metadata philosophy. The philosophy and the way of working were developed in a research project at HAN niversity in The Netherlands in co-operation with the Dutch system house Atos Origin to overcome datawarehouse ife cycle maintenance problems in the Royal Dutch Airlines (KLM).