sentences: High level data quality and the management of ensuring data quality is one of the key success factors for Data Warehousing projects. The following article describes an approach for Data Quality Management, which is based on theories as well as practical experiences. Starting from effects of insufficient data quality in practice, a definition for information, data and data quality will be worked out. Based on the concept of total data quality management the Data Quality Management (DQM) for Data-Warehouse-System will be described. As key part DQM an approach for operative DQM (planing and measuring data quality) will be illustrated and explained. Finally, based on the research results further conclusions are summarised.