Dec 10, 2024
Power BI Dashboard QA Habits
Small quality checks that prevent last-minute surprises in reporting decks.
Dashboards break trust when metrics drift. These QA habits keep KPI reports aligned with expectations — and they reduce the frantic “why did the number change?” moments right before a steering deck or exec review.
This is a practical playbook you can run before every release and automate over time.
Habits that help
1) Reconcile numbers to the source (every time)
Before publishing, validate that your headline KPIs match the underlying truth:
- Total vs total: compare report totals to the authoritative table/query.
- Slice vs slice: validate key cuts (e.g., top 10 products, regions, channels).
- Trend vs trend: confirm that daily/weekly/monthly shapes align with source aggregates.
Practical ways to do this:
- Create a small “QA” table visual with totals and key breakdowns.
- Keep a reference query (SQL / Lakehouse query / semantic model query) that produces the same numbers.
- Store a screenshot or exported CSV from both sides when releasing a high-visibility change.
2) Standardize KPI definitions (and make them visible)
Misalignment often comes from definitions, not bugs. Lock down:
- Business definition: what is included/excluded (e.g., refunds, reversals, internal traffic).
- Time logic: calendar vs fiscal, timezone, snapshot vs event date.
- Grain: transaction-level vs customer-level vs account-level.
- Dedup rules: what constitutes a unique entity.
Implementation habits:
- Maintain a Measures page in the model (a dedicated measures table).
- Add a short “Metric Definitions” tooltip page or sidebar text on critical KPIs.
- Use consistent naming conventions (e.g.,
KPI – Revenue,KPI – Active Users) so reviewers quickly find measures.
3) Control filters and “hidden” context
A report can look correct while filters quietly change the meaning:
- Confirm page filters/slicers are consistent across pages.
- Check visual-level filters (the easiest place to accidentally hide data).
- Validate interactions (cross-highlighting/cross-filtering) behave as intended.
Helpful trick: add a hidden “debug” card that shows the current filter context (date range, region, segment). It’s a fast sanity check during review.
4) Test incremental refresh and late-arriving data
A common drift source is refresh behavior, not logic:
- Verify that incremental refresh partitions are configured correctly (especially the “detect data changes” column).
- Confirm how you handle late-arriving events (do you backfill yesterday? last 7 days?).
- Re-run validation after a refresh to ensure values stabilize.
If your pipeline backfills, your QA should include a quick check that “yesterday” didn’t unexpectedly move.
5) Validate DAX edge cases (blanks, zeros, and totals)
Most KPI issues show up at the edges:
- Blanks vs zeros (a blank might mean “no data yet,” not “0”).
- Total rows behaving differently from row-level logic.
- Division-by-zero cases and percentage measures.
- RLS and “All” selections.
Habits:
- Use
DIVIDE()instead of/. - Confirm that totals are correct when slicing by dimensions with missing relationships.
- Use explicit
COALESCE()/ blank-handling when the business expects a 0.
6) Check the data model: relationships and ambiguity
If your model is drifting, it’s often because relationships changed:
- Confirm relationship direction and cardinality.
- Watch for accidental many-to-many paths and ambiguous filter propagation.
- Ensure date tables and role-playing dates are intentional and documented.
If you need to support multiple date perspectives (created date vs closed date), prefer explicit measures that switch date relationships intentionally, rather than relying on a single implicit path.
7) Performance QA: keep the report “snappy”
Even “correct” dashboards lose credibility if they lag:
- Use Performance Analyzer to identify slow visuals.
- Reduce visuals that query at very high cardinality.
- Prefer star schema patterns and avoid unnecessary calculated columns.
- Watch out for complex measures repeated across many visuals.
A simple benchmark: open the report fresh and verify core pages render in a few seconds on typical hardware and network.
8) Visual QA: consistency, readability, and export safety
Last-minute surprises often happen in the deck export, not in Desktop:
- Validate layout at common export sizes (PDF, PowerPoint).
- Check number formatting (thousand separators, decimals, currency symbols).
- Confirm conditional formatting doesn’t mislead (e.g., red/green with no legend).
- Ensure legends, titles, and axis labels don’t truncate on smaller screens.
For exec-ready reports, keep a consistent “visual language”:
- Same chart types for the same ideas (trend = line, composition = stacked bar, ranking = bar).
- Same colors for the same entities across pages.
- Clear “as of” date displayed somewhere prominent.
A lightweight pre-release checklist
Run this in order (5–15 minutes for small changes; longer for major model changes):
- Refresh the dataset (or confirm the scheduled refresh ran successfully).
- Validate top KPIs (total + 2–3 key slices).
- Validate trend shapes (last 30/90 days).
- Validate filter context and interactions.
- Validate totals, blanks, and edge cases.
- Validate performance on the heaviest page.
- Validate export (PDF/PPT) for layout and formatting.
- Add a short release note: what changed, why, and expected impact.
What I would do differently
Automate more of the QA checks inside the ETL pipeline so issues are caught earlier — but I’d go further and make QA a first-class artifact:
- Data tests upstream: row counts, null thresholds, referential integrity, freshness windows.
- Golden queries: a small set of SQL queries that produce authoritative KPI aggregates, run on every deploy.
- Diff-based checks: compare today’s KPI outputs to yesterday’s and flag unexpected deltas beyond agreed thresholds.
- Release discipline: versioned semantic model changes, a changelog for measures, and a defined rollback plan.
The end goal is simple: humans should review meaning and communication, while automation catches drift and regressions.