INTRODUCTION TO POWER BI
What is Power BI?
Power BI is a software to create & publish reports and data stories from your data-sets. You can make highly interactive, engaging and powerful reports, dashboards or visuals with Power BI. You can connect to any data (Excel files, SQL databases, BI warehouses, Cloud data, APIs, web pages and more), mashup the data, link one table with others, create clickable visualizations and then share them with your audience securely thru Power BI.
Who should use Power BI?
If your job / business or life depends on data, then you can use Power BI. There are two kinds of users for Power BI — Creators & Consumers.
Creators are people who make stuff in Power BI.
Consumers are people who read / view things built in Power BI.
Power BI Creators are typically:
- Reporting professionals
- BI Developers
- Visualization Specialists
- Story tellers / Presenters
On the other-hand, almost anyone can be a Power BI consumer.
How is Power BI different from Excel?
So what, even Excel can create interactive reports. But there are several crucial differences between Power BI and Excel.
- Power BI allows rich, immersive and interactive experiences out-of-box. You can click on a bar in bar chart & other visuals respond to the event and highlight or filter relevant data. You can show graphs & visuals that are very tricky (or impossible) to reproduce in Excel like maps, pictures and custom visuals.
- Power BI works with large data sets There is no artificial limit of 1mn rows in Power BI. You can hookup to a business data set and analyze any volume of data. The limit depends on what your computer (or Power BI server) can process.
- Share and read reports easily You can create reports in Power BI and share them in formats that are universal (i.e. browser pages or apps). This means, your boss need not have Excel or Power BI installed to enjoy the beautiful reports you create.
- Power BI is for story telling while Excel is for almost anything. We can use Excel to simulate pendulum motion, calculate Venus orbit, model a start-up business plan or many other things. Power BI is mainly for data analysis & story telling. If you try to replicate a large, intricate financial model or optimization problem with Power BI, you will either fail or suffer miserably. On the other-hand, if you use Power BI for making reports, running cool analysis algorithms (clustering, outlier detection, geo-spatial patterns etc.) you will wow your colleagues and bosses.
How to get Power BI Software?
Power BI Desktop software is free to download. Just head to Microsoft Power BI website and download the version for your computer.
Things to keep in mind when downloading and installing Power BI:
- Power BI is always changing. Almost every month, Microsoft releases a new version of the software. One simple way to stay on top is to install Power BI thru Microsoft Store (on Windows 10). This way, your computer will automatically update the software whenever there is a new version.
- You do not need PowerBI.com account to use Power BI Desktop. While Power BI may prompt you to login, you can use the software without registering for the online account. However, you can sign up for free PowerBI.com account.
- Login to publish & share your work. Although you can use PowerBI without logging in, you must log-in if you want to publish or share your reports with others.
#1 — Understanding Power BI Desktop UI
Open Power BI Desktop application. After you exit the welcome splash screen, you will see the blank Power BI application. Let’s understand this screen. Here is an illustration explaining 11 important features / buttons in Power BI Desktop.
11 Important features of Power BI Desktop UI
- Ribbon. Find most important and regular stuff in Home ribbon. Navigate to other ribbons for specific functionality.
- Get Data. Use this button to get data from almost anywhere — Excel files, websites, databases, APIs etc.
- View selection, by default you will be on Report view. Change to data or model view to see behind scenes.
- Fields Access the tables and fields (columns) of your data here. Use them in visuals (5) or filters (7) etc.
- Visualizations add charts, tables, maps, filters etc to the report from here.
- Visual Fields, Format and analytics use this area to set up and customize your visualizations (charts etc.) Note the paint-roller, use it to edit colors, fonts, settings etc.
- Filters — set up chart, page, report level filters here. Anything you restrict will be removed from all the linked items.
- Canvas this is where you construct your reports.
- Save your Power BI reports by pressing CTRL+S or clicking on this button. They will be saved as PBIX files.
- Publish the reports with this. You can publish them to online (either free PowerBI.com account or paid plans) so that others can access your reports.
- Add more pages to your report using the + button.
#2 — Load data into Power BI
- Click on Get Data button.
- Select “Excel” as as source.
- Point to the downloaded sample data.
- Select “Table1” in the navigator screen and click on “Load” button.
- Done, your data is loaded.
#3 — Adding Visuals
Working in Power BI feels like playing with your data. This is because of the drag-and-drop nature of report building process. To add a visual,
- Click on the type of visual you want.
- A blank visual will be added to available empty space on your report canvas.
- Select fields from your data and add them to relevant places.
- optionally legend
See this demo to understand the process.
How Power BI visualizations are different…
- Power BI visualizations are always interactive
- They are sorted by default (for ex: descending order for column charts)
- Value field will be the number of chart. You can change the calculation to SUM / COUNT / AVERAGE etc.
- You can even use DAX Measures in the value area of charts
- All visualizations support extra tool-tips (both simple and report-page type tooltips)
- Use Legend field (where available) to see 2nd level detail.
- When you add multiple fields to axis, Power BI adds drill-down buttons to see chart at various levels
#4 — Changing Calculations for the Visuals
You can use two methods to change the calculations for the charts.
- Use default options for calculations — SUM / COUNT / AVERAGE etc.
- Write your own calculations with Power Pivot measures
To change the calculation of a chart with default options, follow below steps.
- Select the power BI visual
- Go to Value field.
- Click on the little down arrow symbol.
- Select the type of calculation you want.
#5 — Understanding Power BI Interactions
Power BI visuals are interactive. This means, if you have more than one chart on a report page, when you click on a particular item on a chart, all other charts respond to the selection and change.
This is quite different from normal Excel charts, but once you get used to it, you will see the true power of Power BI visualizations.
Here is a quick demonstration of Power BI visual interactions.
#6 — Putting it all together — Making a sample report in Power BI
Now that you have some understanding of Power BI, let’s create our first Power BI report. The focus of this report will be,
- For a specific manager
- Show staff distribution by department
- Gender break-down
- All of their staff by salary and rating
This is a fairly simple report, but it does demonstrate the power, elegance and ease of working with Power BI.