Pareto Analysis For Manufacturing

By: Alex Marcy on June 19, 2015
Tagged: Educate Data Analysis Information

How do you prioritize your workload?

You have some hot-button items always at the top of the list. Items usually of great importance to someone else. In the middle are things important t you, and some things at the bottom that would be nice but not critical to complete.

How should you prioritize your workload?

One way is using Pareto Analysis. Here is an example of why a processing plant shutdown over a certain period of time:

Pareto Analysis is simple. Track the number of occurrences of each downtime reason. Sort them in descending order, and put them on a bar chart, with the count on the left y-axis. Next, plot a line of each the percentage each bar contributes to the total downtime count with the value on the right y-axis. This shows you the most common causes of downtime from left to right, and the percentage they are contributing to the whole.

How is this useful?

Sorting information this way shows that if you cut down the 2 most downtime causes, your downtime occurences would drop 50%. To show this, draw a vertical line to the right of a bar to the percentage line. Where this line crosses the percentage line, draw a horizontal line to the right y-axis. This will give you the total percent for the downtime reasons up to that point.

You can apply this method to just about any situation in your plant:

  • Quality issues
  • Safety incidents
  • Maintenance issues

If you are already tracking things like OEE, you can leverage Pareto Analysis tools as a drill-down option in your OEE reports. Drilling down to show the underlying root causes of quality, throughput, or cycle time issues.

Another powerful way to use Pareto Analysis is to go beyond ordering by number of occurrences, and instead by duration. First, imagine you had 100 instances of downtime due to mechanical issues. Second, imagine you have 4 instances of downtime due to power failures. Let's say mechanical issues average 1 minute each, while power failures average 2 hours each. Going by number of occurrences fixing the mechanical issues would be a huge win. If instead you look at reducing the impact on total downtime, power failures have a larger impact.

Wrapping Up

Pareto Analysis can be a powerful tool used to help you prioritize your work load. Please feel free to reach out to us at any time if you have questions. We would be happy to show you some of the automated Pareto Analysis systems we have developed for many different processes.

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