While it is tempting to implement Business Rules at the Infomart Level, that is not where the Business Rules should reside. They should reside in Business Vault. This enables historisation of the Business Rules and introduces auditability. When the Business Rule changes, with historisation it is possible to go back in time and analyze the impact of the Business Rule change. Now if this Business Rule was implemented at the Infomart Level, there would be no history thus no auditability. As a best-practice, the Business Vault tables should be materialized physical TABLES instead of VIEWs.