Power BI in business: the 7 mistakes that kill your reports
Most Power BI reports abandoned after three months fail for the same reasons. The seven most frequent mistakes, and how to correct them.
A Power BI report is abandoned for predictable reasons: a poorly structured data model, measures that give different results depending on the filter, and a page that displays figures without answering a question. Those three causes explain most failures.
1. Importing the tables as they are
Loading ten Excel sheets side by side and relating them by guesswork produces an unstable model. Totals become wrong as soon as a filter is applied, and nobody knows why.
Correction: build a star schema — fact tables surrounded by dimension tables — before drawing the first chart.
2. Doing without a dedicated date table
Without a date table marked as such, time comparisons silently produce wrong results, especially over incomplete periods.
Correction: a continuous date table covering the whole period, marked as a date table in the model.
3. Writing DAX without understanding filter context
This is the most expensive mistake. A measure that is correct in one table becomes wrong in another because the context has changed, and the report loses its credibility at a stroke.
Correction: understand what CALCULATE actually does before using it, and test every measure in at least two different contexts.
4. Cleaning data in the report rather than upstream
Corrections piled into measures make the report unreadable and slow. Every new anomaly adds another patch.
Correction: clean in the query editor, and fix at source wherever possible.
5. Confusing a dashboard with a decision question
A page covered in twenty indicators helps nobody. A report must answer a specific question, asked by a specific person.
Correction: write the question at the top of the page before choosing the charts. If a visual does not contribute to it, it goes.
6. Choosing visuals for their looks
| Question | Use | Avoid |
|---|---|---|
| Comparing categories | Horizontal bars | Pie chart |
| Following a trend | Line chart | Stacked bars |
| Positioning against a target | Bar with a marker | Gauge |
| Showing a distribution | Histogram | Eight-slice doughnut |
| Displaying a single value | Large number | Single-bar chart |
7. Not planning for what comes next
A report with no named owner, no scheduled refresh and no access management dies within months. The first uncorrected wrong figure is enough to send users back to their old spreadsheets.
Correction: name an owner, schedule the refresh, document the measures and set a review rhythm.
Updated Aug. 11, 2026