Waterfall chart- showing +/- difference.

[aa8057]

Hi All,

I'm new to the world of DAX and Power BI and am really interested in creating a Waterfall chart to show the year on year difference between customer applications. I stumbled across a solution myself yesterday, and I managed to create a great looking waterfall exactly how I needed it. Unhelpfully, Power BI crashed and I lost the measure (autosave function anyone?!). I tried all night to replicate what I did but I just can't work it out now . I'm certain there is something fundamental and easy that I am missing and I wonder if you helpful lot could help me out?

Scenario:

I want to count the number of 'customer application ID's' I have in a table for each year and display the+/- difference between each year in a waterfall chart. Each customer has a year of application stored against them.

I have been playing around with the following formula to no avail:

=CALCULATE(COUNT('Customer'[Customer Application Form ID)-CALCULATE(COUNT('Customer'[Customer Application Form ID), PREVIOUSYEAR ('Customer'[Application Year])))

I might have even created a date table yesterday but I honestly tried so many things I can't now remember how I managed it.

The formula above happily counts the total number of customer application ID's for each year and shows this total figure in the waterfall chart. What I'm actually after is the difference between years i.e whether the number was +/- the previous year's figure.

I'd really appreciate it if you could spare a few minutes to walk me through the process.

Thanks so much for any help you can offer!

Matt