How to Make a Pareto Chart in Tableau

A Pareto chart is a surprisingly simple but powerful tool for finding the biggest sources of your problems. By combining a bar chart with a line chart, it helps you apply the 80/20 rule to your data, showing which 20% of factors are causing 80% of your outcomes. This article will walk you through exactly how to build a Pareto chart in Tableau, turning your raw data into a clear guide for prioritization.

What is a Pareto Chart and Why Use One?

The Pareto chart is named after Vilfredo Pareto, an economist who observed that roughly 80% of the land in Italy was owned by 20% of the population. This concept, now known as the Pareto principle or the 80/20 rule, pops up everywhere in business:

• 80% of sales come from 20% of your products.

• 80% of customer complaints relate to 20% of your services.

• 80% of software bugs are caused by 20% of the codebase.

A Pareto chart visualizes this principle to help you separate the "vital few" from the "trivial many." It consists of two key components:

1. A bar chart: This displays individual values for a given category, sorted in descending order from left to right.

2. A line chart: This shows the cumulative total percentage of all categories as you move from left to right.

By putting these together, you can quickly see which categories have the largest impact and where your cumulative percentage crosses the 80% threshold. This is incredibly useful for directing your resources. Instead of trying to fix every single issue, you can focus your efforts on the handful of problems that, if solved, will make the most significant difference.

Preparing Your Data for a Pareto Chart

Before jumping into Tableau, you'll want to make sure your data is structured properly. Fortunately, the requirements are straightforward. Your dataset should contain at least two fields:

• A categorical dimension: This is what you want to analyze and group your data by. Examples include product names, reasons for customer returns, types of defects, or sources of website traffic.

• A numerical measure: This is the value you want to quantify for each category. It could be total sales, the number of returns, the count of defects, or the number of user sessions.

For our example, let's imagine we're an e-commerce company analyzing customer support tickets. We have a simple dataset that lists the reason for each complaint and the number of incidents for each one over the past quarter.

Our goal is to create a Pareto chart that helps us identify which complaint types are most common so we can prioritize operational improvements.

Step-by-Step Guide: Creating a Pareto Chart in Tableau

Once you have your data connected, building the chart involves a few specific steps to create the dual-axis chart and add the necessary table calculations.

Step 1: Create the Sorted Bar Chart

First, we need to create the foundation of our Pareto chart: a descending bar chart that shows the count of incidents for each complaint reason.

1. Open Tableau and connect to your data source.

2. Drag your dimension (in our case, "Reason for Complaint") to the Columns shelf.

3. Drag your measure ("Number of Incidents") to the Rows shelf.

4. Tableau will generate a basic bar chart. To sort it, simply click the descending sort icon in the toolbar, or right-click the "Reason for Complaint" pill in the Columns shelf and select Sort > Sort By > Field, then choose "Number of Incidents" and set the order to "Descending."

At this point, your view should look like a standard bar chart with the highest bar on the left.

Step 2: Add a Dual Axis with a Line Chart

Next, we need to add the line chart component that will eventually show our running cumulative percentage. We do this using Tableau's dual-axis feature.

1. Drag the "Number of Incidents" measure from the Data pane onto the Rows shelf again, placing it to the right of the existing pill. You will now see two identical bar charts, one on top of the other.

2. In the Marks card area, you’ll see separate cards for each of your measures. Click on the card for the second SUM(Number of Incidents).

3. Change its mark type from Automatic (which is currently a Bar) to Line.

4. Now, right-click the second SUM(Number of Incidents) pill on the Rows shelf and select Dual Axis. This will overlay your line chart on top of the bar chart.

5. Finally, to ensure the two charts are using the same scale, right-click the right-side axis (the one for the line chart) and select Synchronize Axis.

Step 3: Create the Running Total Calculation

This is where the magic starts. We need to transform the line from showing the raw count into a cumulative running total.

1. Right-click the second SUM(Number of Incidents) pill on the Rows shelf (the one controlling the line chart).

2. Hover over Add Table Calculation.

3. In the Table Calculation dialogue box that appears, make the following selections:

   • Calculation Type: Running Total

   • Summarize values using: Sum

   • Compute Using: Table (across) or your specific dimension (e.g., "Reason for Complaint"). "Table (across)" typically works if your setup is standard.

Do not close the dialogue box yet. Your line chart should now show an upward curve, representing the cumulative sum of incidents as you move across the categories.

Step 4: Add a Secondary Calculation for Percent of Total

A running total is great, but a Pareto chart traditionally uses a percentage scale. We can add a second table calculation on top of our first one to convert the running sum into a percentage.

1. Within the still-open Table Calculation dialogue box, check the box at the bottom that says Add Secondary Calculation.

2. Set the Secondary Calculation as follows:

   • Secondary Calculation Type: Percent Of Total

   • Compute Using: Table (across) or "Reason for Complaint."

3. Click the X to close the dialogue box.

Now, your line chart should still show the same upward curve, but the axis on the right side will have changed from a count of incidents to a percentage, ranging from 0% to 100%.

Step 5: Final Formatting and Polish

Your Pareto chart is functionally complete, but a little formatting goes a long way in making it easy to read and understand.

• Adjust Colors: On the Marks card, you can change the color of the bars and the line to provide better contrast. A blue bar and an orange or black line often work well.

• Axis Titles: Right-click on each axis and select Edit Axis to give them meaningful titles. The left axis could be "Number of Incidents" and the right "Cumulative Percent of Total."

• Hide the Right Axis Header: Since you've already synchronized the axes, and the percentage format speaks for itself, you can optionally right-click the right axis header again and uncheck "Show Header" to declutter the view.

• Add Labels: Drag the "Number of Incidents" measure to the Label mark on the first Marks card to show the value on top of each bar. You can do the same for the line chart to show the cumulative percentage at each point.

• Add a Title: Double-click the sheet title to give your chart a descriptive name like "Pareto Analysis of Customer Complaints."

Bonus Tip: Add an 80% Reference Line

The whole point of a Pareto chart is to find that 80/20 cutoff. Adding a reference line at the 80% mark makes this incredibly easy for your audience to see.

1. Go to the Analytics pane (next to the Data pane).

2. Drag Reference Line from the pane and drop it onto your chart. When you drag it, Tableau will give you options to drop it on the Table, Pane, or Cell. Drop it on Pane.

3. In the Edit Line dialogue box:

   • Set the Value to a Constant.

   • Enter 0.8 into the value field. This represents 80%.

   • You can change the label from "Constant" to "80% Threshold" or something similar using the Label dropdown menu.

   • Adjust the line’s appearance as desired (e.g., dotted, different color).

4. Click OK.

Now you have a horizontal line stretching across your chart at the 80% level, making it clear which categories fall below that crucial threshold.

How to Read and Interpret a Pareto Chart

Reading your newly-created chart is straightforward. The bars, sorted from highest to lowest, immediately tell you the biggest individual contributors to the total. In our example, "Late Delivery" is clearly the biggest problem, followed by "Damaged Product."

The line, representing the cumulative percentage, tells the bigger story. Looking at where your reference line intersects with the cumulative percentage line, you can identify the "vital few."

In our example visualization, you'd find a small number of categories contribute to 80% of complaints. The categories to the left of where the running total line crosses the 80% mark - likely just "Late Delivery", "Damaged Product", and "Incorrect Item Shipped" - collectively account for about 80% of all support tickets. This gives you a data-driven justification to focus your limited time and resources on tackling shipping and fulfillment issues first, rather than getting distracted by less frequent problems like billing questions.

Final Thoughts

Building a Pareto chart in Tableau is a fundamental skill that transforms a simple dataset into a strategic decision-making tool. By combining a sorted bar chart with a running percentage line, you create a clear visual guide that helps you prioritize your efforts on the problems that truly matter, delivering the most impact with the least amount of work.

While mastering tools like Tableau unlocks powerful analysis, a lot of time is still spent on setting up a workbook, creating dual axes, and managing table calculations. We built Graphed because we believe getting insights shouldn't be so complex. By connecting your data sources and simply asking questions like "Show me a Pareto chart of customer complaints by reason," you get an interactive dashboard in seconds, allowing you to focus on the insight, not just the setup process.