How to document your data and DAX in Power BI

This post is all about documenting what your columns and DAX measures are all about (and maybe why they exist) in Power BI.
Your datasets (whether you use them with Power BI or not) should be documented regardless, but that’s a data governance topic for another place, but documenting your data WITHIN your Power BI report is incredibly useful and will help you (and anyone else using the file) know a column or DAX measure is for (or why you’ve created it for the report).
We’re going to use a very simple dataset to demonstrate how this works, and if you’d like a copy of the Power BI file I use in the below video and written instructions, you can download it here.

Video:
Written Instructions:

We’re starting here with a super simple Power BI file… I just made a quick bar graph with the small dataset we have, but we’re not going to be in this view of Power BI at all really as we talk about documentation, we’ll be in our Model view, so let’s switch to that.

I always say that documentation is like insurance. It can be a pain in the butt to make those payments, but when you need it you will be so thankful that you have it.
Data documentation, and Power BI documentation is also super important as it lets you record what your columns and DAX measures are used for. This is beneficial not only for you, so if you don’t work with a report for a long time and then have to remember things about the columns or DAX measures, you’ve documented just that.
This is also useful for other people if they are using your Power BI report file in the future. They will know what the columns and DAX measures are for.
This is nice and easy to do here in the Model View of a Power BI report.
Our little simple dataset only has 3 columns. Our Location column has cities in it. Our Pet column has well, types of pets in it, and our Values column is… well what is it?
Your first instinct may be to assume that Value means how many pets of each type are in the different cities, but maybe it doesn’t. Maybe it’s how many have been sold in the last year. Or the last 6 months. Or have been accidentally sat on by toddlers. 🙁
It’s good to record just WHAT data is about.
Let’s document what our Value column is about by going to our Model view and selecting that column in the little table box in the main part of our screen.

When we do that, we get a Properties pane opening up where we can set a lot of things, but for now we’re going to put all of our attention on the “Description” box in our Properties pane.
This is where we can describe our data.

This description can be as long as necessary. I have not yet come up against a character or word limit in this, but there probably is one, but it’s huge… you can write a lot in here.
You can click on the other columns and see the same Description box.
Also for any DAX measures that you make. Easy-peasy documentation.
As well, you can click on the entire dataset and get the same Description box, so you can describe the dataset as well.

It’s nice and easy to document your datasets, columns and DAX measures, right IN your report.
Take care everyone,
Joe.
Like these posts but need more formal (but still engaging and fun) training in Power BI? Contact me, Joe Travers or at joe@traversdata.com. I got you.

0 Comments