The enterprise data warehouse bus matrix is the essential tool for designing and communicating the enterprise data warehouse bus architecture. The rows of the matrix are business processes and the columns are dimensions. The shaded cells of the matrix indicate whether a dimension is associated with a given business process. The design team scans each row to test whether a candidate dimension is well-deﬁned for the business process and also scans each column to see where a dimension should be conformed across multiple business processes. Besides the technical design considerations, the bus matrix is used as input to prioritize DW/BI projects with business management as teams should implement one row of the matrix at a time.
The detailed implementation bus matrix is a more granular bus matrix where each business process row has been expanded to show speciﬁc fact tables or OLAP cubes. At this level of detail, the precise grain statement and list of facts can be documented.