Today, we will talk about WhatIf Analysis in Tableau. WhatIf Analysis is when you propose a hypothetical scenario and use it to see how it will affect your business. A simple example is, how much will my profit increase if I stop doing business with unprofitable customers? As usual, we will use the Superstore Sales sample data set in Tableau.
Step 1:
 Find the unprofitable customers

Unprofitable Customers 
Step 2:
 Create a line graph of Profit per Year, segregated by Profitable/Unprofitable Customers
 Use the Pages Shelf to hide the Unprofitable line.

Profit by Year, from Profitable Customers 
Step 3:
 Calculate the Total Profit using both Profitable and Unprofitable Customers
 Create the following table calculation

Total Profit 
Step 4:
 Use this table calculation to create a synchronized, dualaxis line chart.

Total Profit and Profit from Profitable Customers by Year 
As you can see, there is a pretty significant increase in Profit if we stop doing business with unprofitable customers. Some of you may say, "This isn't the kind of WhatIf Analysis I'm used to!!!" You're right. This example was useful for showing the strength of Tableau in the area.
Now, let's look a more traditional WhatIf Analysis. What would happen to my profit if I decreased my shipping cost by X%?
Step 1:
 Create a parameter for the X%

Shipping Cost Decrease Percentage 
Step 2:
 Calculate the new profit
 Create the following calculated field

New Profit 
Some of you might be asking, "Why did you calculate profit that way?" The simple answer is, I didn't have the right variables in my data set to calculate Profit the traditional way, i.e. Profit = Sales  Costs. At its simplest, this way adds the Shipping Cost back into the Profit. There are some much more complicated ways to do something like this, but for the sake of simplicity, we'll keep it like this for now.
Step 3:
 Create a line chart to compare Profit and New Profit by Year

Profit and New Profit by Year 
As you can see, if you can decrease shipping costs by 20%, you can increase profit by about 1% or 2%. While these aren't substantial numbers, there's a very important concept to remember. Shipping is a notoriously inefficient business. It's not uncommon for companies to reduce shipping costs 20% or 30% just by using a new piece of technology or creating a new initiative. Also, it's pretty easy to make your boss smile if you can show him a way to increase his profits by a few percent each year. I hope you found this informative. Thanks for reading.
Brad Llewellyn
Associate Consultant
Mariner, LLC
llewellyn.wb@gmail.com
https://www.linkedin.com/in/bradllewellyn