Our goal in this blog to explain what a Pareto Chart is, why it’s useful to manufacturers, and how it’s used within manufacturing analytics to help identify and fix problems on the factory floor. We’ll also use a specific example from a SensrTrx dashboard to show how you can use data gathered from a bottling line to find bottlenecks. For that example, scroll to the end of the blog.
To recap, we’ll cover:
- What are quality tools in manufacturing?
- What is a Pareto Chart and what is it used for?
- Are a Pareto Chart and Pareto Analysis the same thing?
- Real-life example: Find a bottleneck on a line using a Pareto Chart.
Measuring and evaluating quality on the factory floor is vital to each and every manufacturer, regardless of the product being made. For years, quality experts have relied on 7 tools to determine the quality of a product.
- Cause-and-effect diagram
- Check sheet
- Control sheet
- Pareto Chart
- Scatter diagram
Most popular of those tools is the Pareto Chart, a visual graphing tool used by all manufacturers to evaluate quality on the floor.
Pareto Chart: A Pareto Chart is a type of graph that “contains both bars and a line graph, where individual values are presented in descending order by bars, and the cumulative total is represented by a line.” Source: Wikipedia
The Pareto Chart has many names and is also commonly referred to as a Pareto Analysis or Pareto Diagram. Regardless of the name used, a Pareto is useful in manufacturing for recording downtime and scrap reasons as well as finding bottlenecks on production lines. (There are many other uses for the Pareto Chart in other industries, but for the sake of this blog, we’ll keep it limited to the manufacturing industry.)
For a little bit of history, the Pareto Chart was developed by economist Vilfred Pareto in 1897 to represent the uneven distribution of wealth; he believed that 80% of the wealth was controlled by 20% of the population. The development of the 80-20 rule eventually transformed into the Pareto Principle we know today, which attributes 80% of problems to be caused by 20% of factors.
Years later, this chart became synonymous with manufacturing due to its ability to easily highlight the top causes of defects and bottlenecks.
What is a Pareto Chart Used For?
The purpose of the Pareto Chart is to visually illustrate the most important factors of a particular issue or problem.
In the world of manufacturing, a Pareto is often used to highlight downtime and scrap reasons and bottlenecks on the line. Shown in the example Pareto below, you can see how the chart highlights specific reasons for downtime: end of shift cleaning, shortstop, dial-in, tool change, and changeover.
Using the chart you can analyze the causes of downtime on the factory floor and determine a course of action for fixing the problems.
With manufacturing analytics software, one of the key benefits is being able to easily display aggregate data to provide trend analysis and be available in Pareto Charts so data can be viewed in context.
Simply another name for a Pareto Chart, a Pareto Analysis helps, as we said before, identify common causes of persisting issues. Let’s take a minute to dive even further into how a Pareto Chart, or Analysis, can impact manufacturing:
- Identify key causes of problems, whether that be downtime, scrap, or even bottlenecks
- Organize a plan of action using the identified causes
- Improve productivity, efficiency, and profitability
So, how do you create Pareto Analysis to reflect the data gathered from your own shop floor?
How to Make a Pareto Chart to Identify Bottlenecks
In the traditional sense, creating a Pareto Chart is very much a manual process. To do this, you would physically write out a list of problems, write out the root causes of problems, score the problems and group by score, then create a chart – tedious, right?
Only after you had physically created a Pareto would you be able to identify which of the root causes of problems were in that 20% bracket of causing 80% of problems.
Luckily, technology has come a long way. There is no need to draw out a chart by hand. Using the data gathered from a manufacturing analytics software, a Pareto Chart will be created for you, with just a view clicks of your mouse, using real-time data from the floor.
Let’s go through an example of how to use a Pareto Chart to identify bottlenecks on the line. Below, you’ll see a Pareto Chart from the bottling line dashboard. (Remember, no manual work your part – this is created for your within SensrTrx.)
After looking at the chart, you can see the beginning of a bottleneck in either the station or the line as a whole. Something is happening that takes the line down and creates a bottleneck, ceasing production further down the line. You can see most of the downtime is related to the whole bottling line, but there are clear problems at the filler, too.
To supplement data, below is a screenshot of specific downtime reasons. Sorting by total minutes, you’ll see sanitation on the line is the number 1 reason for downtime, but sanitation is required each time there is a changeover on the line so there’s nothing you can do about that particular downtime reason. On to the next.
If you look to the next line in the graph, you’ll see that call maintenance on the filler and the bottling line as a whole are top downtime reasons, indicating a problem that needs to be addressed.
The Pareto Chart is helping you figure out where the largest percentage of downtime is coming from, with additional reasoning data.
In this specific example, there is an issue with the filler that needs your attention. Go out and view the filler. Watch what’s going on. Talk to maintenance about their findings, discuss the machine with your operators. This would be a good time to start the “5 Why’s” process to determine the root cause of the problem.
A Pareto Chart Helps Manufacturers Determine Root Cause
Manufacturing analytics software will help you collect information from the line and showcase the problem areas. When those problem areas are highlighted, you are able to gather insights and determine a plan to fix any issues.
The Pareto Chart is a simple, yet effective visual tool for determining the root cause of problems, downtime, scrap, or bottlenecking. Using the graph, organizations can quickly create a plan of action in tackling problems.