A Pareto chart or pareto graph displays the importance of various factors in decreasing order in columns along with cumulative importance in a line. Pareto charts are often used in quality control to display most common reasons for failure, customer complaints or product defects.
The principle behind pareto charts is called as pareto principle or more commonly the 80-20 rule. According to wikipedia,
The Pareto principle (also known as the 80-20 rule,[1] the law of the vital few, and the principle of factor sparsity) states that, for many events, roughly 80% of the effects come from 20% of the causes.
The pareto chart is a great way to do the pareto analysis. Today, we will learn how to use excel to make a pareto chart.
See an example pareto chart of visits to this website:
(Please note that in this example, the 80/20 rule does not hold as I have chosen very small sample of data. In reality, the 80/20 principle applies to my website as well)
Making a Pareto Chart in Excel
In order to make the pareto chart in excel, first you must have the data ready. Once we have the values for each cause, we can easily calculate cumulative percentages using excel formulas. We will also require a dummy series to display the “cutoff %” in the Pareto chart.
I have arranged the data in this format. You can choose any format that works for you.
Once you have the data ready, making the pareto chart is a simple 5 step process.
1. Make a column chart using cause importance data
In our case, we select the first 2 columns in the above table and then make a new column chart.
2. Add the cumulative %s to the Pareto Chart as a line
Select the third column, press ctrl+c (copy). Now select the chart and press ctrl+v (paste). Excel will add another column series to the chart. Just select it and change the series chart type to “line chart”. Learn more about combining 2 different chart types in excel combo charts.
3. Move the cumulative %s line to secondary axis
Select the line chart, go to “format data series” (you can also press ctrl+1) and change the axis for this chart series from “primary” to “secondary”.
4. Add the cut-off % to the pareto chart
Select the fourth column in our data table, copy and paste it in the chart. This should ideally be pasted as a new line chart. If not, follow step 2 for this as well.
5. Finally, adjust formatting to make the final pareto chart
Now, our basic pareto chart is ready. We should adjust the chart formatting to make it more presentable. Once you are done, the final output will be something like above chart.
Download the Pareto Chart Template in Excel
Click here to download the excel pareto chart template.
When to use Pareto Chart?
Pareto charts can be used,
- During quality control to analyze the causes of defects and failures
- When you want to focus your resources on few important items from a large list of possibles
- To tell the story that attacking problem A might be better than solving problem C, D and F
Pareto charts and pareto analysis has great practical uses for almost anyone in a managerial role.
Have you used Pareto analysis or Pareto charts in your job?
Pareto principle is the first real management lesson I have learned during my MBA. It is the topic for my first presentation too. During the presentation, Anoop, my jovial team mate said, “80-20 principle can be tested anywhere. For eg. in most parties 80% of the beer will be consumed by 20% of people”, and the whole class started laughing.
Jokes apart, I think pareto principle is a very powerful idea told in an extremely simple way. I use the pareto analysis to find best way to invest my time. What about you? Tell me about your experiences of using pareto analysis using comments.
Related Material:
14 Responses to “Group Smaller Slices in Pie Charts to Improve Readability”
I think the virtue of pie charts is precisely that they are difficult to decode. In many contexts, you have to release information but you don't want the relationship between values to jump at your reader. That's when pie charts are most useful.
[...] link Leave a Reply [...]
Chandoo,
millions of ants cannot be mistaken.....There should be a reason why everybody continues using Pie charts, despite what gurus like you or Jon and others say.
one reason could be because we are just used to, so that's what we need to change, the "comfort zone"...
i absolutely agree, since I've been "converted", I just find out that bar charts are clearer, and nicer to the view...
Regards,
Martin
[...] says we can Group Smaller Slices in Pie Charts to Improve Readability. Such a pie has too many labels to fit into a tight space, so you need ro move the labels around [...]
Chandoo -
You ask "Can I use an alternative to pie chart?"
I answer in You Say “Pie”, I Say “Bar”.
This visualization was created because it was easy to print before computers. In this day and age, it should not exist.
I think the 100% Bar Chart is just as useless/unreadable as Pies - we should rename them something like Mama's Strudel Charts - how big a slice would you like, Dear?
My money's with Jon on this topic.
The primary function of any pie chart with more than 2 or 3 data points is to obfuscate. But maybe that is the main purpose, as @Jerome suggests...
@Jerome.. Good point. Also sometimes, there is just no relationship at all.
@Martin... Organized religion is finding it tough to get converts even after 2000+ years of struggle. Jon, Stephen, countless others (and me) are a small army, it would take atleast 5000 more years before pie charts vanish... patience and good to have you here 🙂
@Jon .. very well done sir, very well done.
good points every one...
I've got to throw my vote into Jon's camp (which is also Stephen Few's camp) -- bars just tend to work better. One observation about when we say "what people are used to." There are two distinct groups here (depending on the situation, a person can fall in either one): the person who *creates* the chart and the person who *consumes* the chart. Granted, the consumers are "used to" pie charts. But, it's not like a bar chart is something they would struggle to understand or that would require explanation (like sparklines and bullet graphs). Chart consumers are "used to" consuming whatever is put in front of them. Chart creators, on the other hand, may be "used to" creating pie charts, but that isn't an excuse for them to continue to do so -- many people are used to driving without a seatbelt, leaving lights on in their house needlessly, and forwarding not-all-that-funny anecdotes via email. That doesn't mean the practice shouldn't be discouraged!
[...] example that Chandoo used recently is counting uses of words. Clearly, there are other meanings of “bar” (take bar mitzvah or bar none, for [...]
[…] Grouping smaller slices in pie chart […]
Good article. Is it possible to do that with line charts?
Hi,
Is this available in excel 2013?