Module 1: Power BI Foundations
The Power BI Ecosystem
Many organisations still run on spreadsheets emailed around every Monday, each one slightly different from the last. Power BI replaces that habit with a single, refreshable source of truth that people can explore themselves. Before you build anything, it helps to understand the pieces of the Power BI family and how they fit together, so you know which tool to open for each job and what your colleagues will need in order to see your work.
The main components
| Component | What it is | What you use it for |
|---|---|---|
| Power BI Desktop | A free Windows application | Connecting to data, cleaning it, building the data model, writing DAX and designing reports |
| Power BI Service | The cloud platform at app.powerbi.com | Publishing, sharing, dashboards, scheduled refresh, apps and access control |
| Power BI Mobile | Apps for phones and tablets | Viewing reports and dashboards on the move |
| On-premises data gateway | Software installed on a machine in your network | Letting the Service refresh data that lives on local servers or files |
| Power Query | The data preparation engine inside Desktop (and other Microsoft tools) | Importing, cleaning and shaping data before it enters the model |
| DAX | Data Analysis Expressions, a formula language | Creating measures and calculated columns |
Power BI is also part of Microsoft Fabric, Microsoft's wider analytics platform. As a beginner you can ignore most of Fabric; everything in this course works with Power BI Desktop and the Power BI Service.
The typical workflow
- Get data. Connect Desktop to sources such as Excel workbooks, CSV files, SQL databases, SharePoint lists or online services.
- Transform. Use Power Query to remove junk rows, fix data types and reshape tables.
- Model. Create relationships between tables and add a date table.
- Calculate. Write DAX measures such as total sales, margin percentage and growth on last year.
- Visualise. Build report pages with charts, tables, cards and slicers.
- Publish and share. Publish to a workspace in the Service, set up refresh, and share with your audience.
Notice that visuals come near the end. Most of the value, and most of the work, sits in clean data and a sound model.
Licensing in plain terms
Power BI Desktop is free to download and use. Publishing to your personal "My workspace" in the Service is possible with a free account, but sharing content with colleagues generally requires a paid licence such as Power BI Pro or Premium Per User for both the person sharing and the people viewing, unless the content sits in a workspace backed by a Premium or Fabric capacity. Microsoft changes plans and prices from time to time, so check the current Power BI pricing page before you budget. Power BI Desktop runs on Windows only; Mac users typically use a Windows virtual machine or a Windows computer.
A worked example
A distribution company in Nairobi sends a sales spreadsheet to its five regional managers every Monday. The finance assistant spends most of Monday morning copying data from the accounting system export into the workbook, and managers still argue because their versions differ.
With Power BI, the assistant connects Desktop to the weekly export folder, cleans the data once in Power Query, builds a model with sales, products, customers and a date table, and creates measures for sales, gross margin and growth. She publishes the report to a shared workspace and schedules a refresh each morning. Each regional manager opens the same report, filters to their region with a slicer, and sees identical numbers. Monday mornings are now spent discussing results instead of preparing them.
Common mistakes to avoid
- Starting with charts. A pretty report on a messy model will mislead and break.
- Ignoring licensing until launch day. Confirm early who needs which licence to view your work.
- Treating Power BI like Excel. You do not type numbers into cells; you build a model and let measures calculate.
- Keeping data on a personal laptop. If the source file lives only on your machine, scheduled refresh will fail when you are away.
In the next lesson you will start the workflow properly with Power Query.
Exercise
Download and install Power BI Desktop from Microsoft's official site or the Microsoft Store if you use Windows. Open it, find the Get data button, and list five data source types your organisation or a business you know uses. For each source, write whether it lives in the cloud or on a local machine, because that affects refresh later.
Key points
- Desktop is where you build; the Service is where you share and refresh.
- The workflow is get data, transform, model, calculate, visualise, then share.
- Sharing usually needs a paid licence or capacity, so check Microsoft's current pricing.
- Most of the value lies in clean data and a sound model, not in the visuals.