Many applications have been commercially developed for use with data warehouses and OLAP cubes. Each application has unique requirements that may or may not require design changes to a data warehouse for effective operation of the application. Some applications operate on the data warehouse to provide additional analysis, management, or maintenance capabilities. Others are client applications that provide analysis capabilities for end users. Commercial applications usually require setup and configuration before they can use data warehouse data effectively. Applications may also need configuration adjustments in order to accommodate changes in the data warehouse and updates to data.