The fundamental problem: objective confusion
An exploration dashboard is not a steering dashboard. Most failed dashboards try to be both at once. Define upfront: who consults this, to make what decision, in how much time?
The 5 principles of a working dashboard
The rule of 3
3 KPIs maximum in the first row, large and without noise. Each KPI has a current value, a reference value and a trend indicator.
Visual hierarchy
The eye follows a Z or F logic. Place your most important information at the top left. Size encodes importance.
Colour with intention
Red for alerts. Green for successes. Blue for neutral information. Never more than 3 colours in a steering dashboard. Always think about colour-blind users.
The 5-second test: show your dashboard to someone for 5 seconds, cover it, and ask what they retained. If not your 3 main KPIs, redo the visual hierarchy.
Context is mandatory
A number without context says nothing. Always compare to the previous period AND to the target. Specify the period.
Global filters, not local
Filters must apply to the entire dashboard, not just one chart.
The 3 most frequent mistakes
The pie chart with 8 slices (unreadable). 3D charts (always misleading). Y-axes not starting at zero on bar charts (visual manipulation).
Designing dashboards that read fast, in Power BI as much as Tableau, takes several modules of the Data Analyst Bootcamp.
