KB article

A Context Test Harness for Power BI Models

A test harness validates that key questions return stable results.

arf-kbcontext-stabilitycontext-test-harnessdeterministic-querycontext-volatility

TL;DR

  • Define representative queries and expected outcomes.
  • Use them to detect context regressions.

The problem

  • Context issues are hard to detect until users complain.
  • Model changes can silently break answers.

Why it matters

  • Tests provide early warning for instability.
  • They enable safe iteration on the model.

Symptoms

  • Unexpected changes in KPI values after model updates.
  • AI answers that drift without data changes.

Root causes

  • No regression tests for filter context.
  • Model updates lack validation checks.

What good looks like

  • A small set of representative queries with expected ranges.
  • Regular test runs before deployment.

How to fix

  • Define 10–20 representative questions.
  • Capture expected outcomes or ranges.
  • Run tests after every model change.

Pitfalls

  • Testing too many edge cases and ignoring core KPIs.
  • Using stale expected values.

Checklist

  • Test harness defined and documented.
  • Tests run on every release.
  • Failures reviewed and resolved.

Framework placement

Primary ARF layer: Context Stability. Diagnostic bridge: data-movement-reliability, semantic-reliability, execution-reliability.