A data warehouse (DWH) is used to manage and control business processes. The basis for a customer-oriented value chain is ensured by customer-relevant information. For this purpose, information is extracted from customer data from which conclusions can be drawn about the market and the customers. This knowledge can be used for actions such as the development of a service.
Data warehousing is the data basis for analysis and decision support for management. Data warehousing is defined in a process-oriented way, is subject- and subject-related and thus independent of the source, it can be integrated thanks to a company-wide terminology, it is furthermore reproducible and has a temporal reference.
Similar to the OSI reference model, there is a six- layer reference model for data warehouses from the META Group. In this model, the first layer describes the sources of the data warehouse. This layer is the feedback layer and includes communication, publication, workflow, and the Web.In the second layer, information generation, the data warehouse infrastructure is defined, just as in layers three - middleware - and four - data warehouse. Thus in layer two the calculation, aggregation, analysis, modeling and visualization, in layers three and four the storage and management of the data. Layer five, called the data access layer, includes online analytical processing( OLAP), data mining and data visualization. In the top layer six, called operational layer, the process ofquality assurance, result presentation and information delivery via internal and external sources takes place.