Without conformed dimensions, each team builds its own "customer" or "product" table with slightly different keys and definitions. Then leadership asks for a cross-process metric and nobody can join cleanly.
Sales dim_customer.customer_id = 'C-100' (CRM id) Marketing dim_user.user_id = 'u_9f3' (app id) Support dim_account.acct_num = 55102 "Revenue per active support customer" becomes a reconciliation project
What conformity unlocks
- Drill-across reports: orders + shipments + tickets on one customer
- Consistent filters (region, segment) across dashboards
- One SCD policy so history does not fork by team
- Lower duplicate ETL logic
Cost
Up-front alignment: agree on natural keys, survivorship, and attribute ownership. Worth it once you have more than one fact process.
Interview tip
Tell a short story: two facts, two conflicting customer dims, broken executive dashboard. Then say conformed dims prevent that.