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Mary Ngure
Mary Ngure

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PowerBI; Relationships, Schemas & Dashboards

When I started learning Power BI, I thought dashboards were mostly about choosing the right charts.

Then I discovered data modeling.

Everything clicked.

I realized that dashboards aren't powered by visuals, they're powered by relationships.

The Mistake I Used to Make

Coming from Excel, I was used to keeping everything in one large table.

It worked... until the data became larger and more complex.

Duplicate information increased.

Performance slowed down.

And maintaining the dataset became frustrating.

Power BI introduced me to a completely different way of thinking.

Instead of one giant spreadsheet, data is organized into related tables.

Understanding Relationships

Relationships allow tables to communicate using common fields, often called keys.

For example:

  • A Sales table stores transactions.
  • A Products table stores product information.
  • A Customers table stores customer details.

Rather than repeating product names thousands of times, Power BI connects the tables using Product IDs.

This keeps the model cleaner, faster, and easier to maintain.

Discovering Star Schema

One concept that completely changed my understanding was the Star Schema.

Instead of random tables connected everywhere, the model is organized into:

Fact Table

Contains measurable business events such as:

  • Sales
  • Revenue
  • Quantity Sold
  • Profit

Dimension Tables

Contain descriptive information like:

  • Customers
  • Products
  • Locations
  • Dates

The fact table sits in the center, while the dimension tables surround it—forming a star.

It's surprisingly elegant.

And it's one of the reasons Power BI performs so efficiently.

Why Good Models Create Better Dashboards

Once relationships were configured correctly, dashboard creation became much easier.

Instead of manually combining data for every visual, Power BI automatically understood how everything connected.

Slicers filtered multiple visuals correctly.

Measures returned accurate results.

Cross-filtering worked naturally.

It felt like the model was doing half the work for me.

Dashboard Design Is More Than Pretty Colors

Building dashboards taught me another important lesson.

A dashboard isn't a decoration.

It's a decision-making tool.

Now, whenever I design one, I ask:

  • What question should this answer?
  • What KPI matters most?
  • What action should someone take after seeing this visual?

Those questions have become more important than choosing between a bar chart or a line chart.

My Growing Power BI Workflow

As I continue learning, my process has become surprisingly consistent:

  1. Understand the business problem.
  2. Clean the data.
  3. Build relationships.
  4. Design a star schema.
  5. Create measures.
  6. Build visuals.
  7. Refine the dashboard until it tells a clear story.

Each step builds on the previous one.

Skipping one almost always creates problems later.

Final Thoughts

Power BI has taught me that great dashboards aren't created in the report view.

They're created through thoughtful data modeling.

The visuals may be what users notice first, but relationships are what make those visuals meaningful.

I'm still learning, but every project reinforces the same lesson:

Clean data is important.

Well-designed models are powerful.

And dashboards are simply the final chapter of a much bigger story.

Top comments (1)

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Mwenda Harun Mbaabu

Good work Mary 👏🏿