Self-service fails when every analyst publishes a personal datamart. Teach five non-negotiables; block certification when any fail.
The five rules
- Star schema: facts + dimensions; no 40-column flat sheets as the long-term model.
- Mark as date table on a real Date dimension before any time intelligence.
- Single-direction relationships by default; bidirectional needs review.
- Measures live on a measures table with descriptions — not random columns on facts.
- Production reports come from a shared workspace with scheduled refresh — not My Workspace + email PBIX.
How trainers verify
In review, open Model view: count bidirectional edges, confirm Date marking, spot-check View Native Query on one query, and check dataset settings for gateway binding. If refresh history shows Failed with path or credential errors, send back to source hygiene — do not “train visualization tips” over a broken model.
Graduation artefact: one certified-candidate dataset that passes the five rules and a View as RLS test if the domain requires regional filters.