Power BI step by step
Power BI from Microsoft is the most widely used BI tool in companies, and Power BI Desktop is free on Windows. Every report follows the same journey:
| 1 · Get data | From Excel, a SQL database, an ERP or CSV files. |
| 2 · Power Query | Cleaning and transforming in recorded steps: drop columns, standardise values, merge tables. The same ETL you learned. |
| 3 · Model | Link tables with relationships in a star: facts in the middle, dimensions around them. |
| 4 · DAX measures | Formulas that compute KPIs and respond to filters. |
| 5 · Report | Drag charts, cards and slicers onto the page. |
| 6 · Publish | Upload to the Power BI service and share with the team (needs a licence). |
DAX is Power BI's formula language. The key distinction: a measure is calculated on the fly according to filters, while a calculated column is computed once per row and stored. Always use measures for KPIs:
DAX
Total Sales = SUM ( Sales[Amount] ) Gross Margin % = DIVIDE ( [Total Sales] - SUM ( Sales[Cost] ), [Total Sales] ) Riyadh Sales = CALCULATE ( [Total Sales], Branch[City] = "Riyadh" )
Watch outUse
DIVIDE instead of the slash: if the denominator is zero it returns blank rather than an error. And CALCULATE is DAX's most important function: it evaluates a measure under conditions you set.Alternatives: Tableau is excellent for visualisation and common in large companies, and Google's Looker Studio is free and simple. The concepts are the same in all three: master one and the others come quickly.