So far, data warehousing has often been discussed in the light of complex OLAP queries and as reporting facility for operative data. We argue that business planning as a means to generate plan data is an equally important cornerstone of a data warehouse system, and we propose it to be a first-class within an OLAP engine. We introduce an abstract model describing relevant aspects of the planning process in general and the requirements it poses to a planning engine. Furthermore, we show that business planning lends itself well to parallelization and benefits from a column-store much like traditional OLAP does. We then develop a physical model specifically targeted at a highly parallel columnstore, and with our implementation, we show nearly linear scaling behavior. Categories and Subject Descriptors H.2.4 [Database Management]: Systems--Parallel databases