A Pareto Chart is one of the seven basic tools of quality which helps to determine the most frequent defects, complaints, or any other factor. Vilfredo Pareto is the eponym of this diagram.
7 BASIC QUALITY TOOLS
- Fishbone (Cause and Effect or Ishikawa) Diagram
- Check sheet
- Control charts
- Pareto chart
- Scatter diagram
In order to make a Pareto Analysis, you need datas which are broken down into classes, and you should count how often each class occurs.
The counts are represented as the bars from largest to smallest and from left to right in the chart.
The most important class or category is represented by the biggest bar which is on the left. The least important category is symbolized by the smallest bar which is on the right. In other words, the bars on the left are more important than the bars on the right.
There is a cumulative percentage line in The Pareto Chart which helps to analyze the effect of each category. The slope of the cumulative percentage line changes based on the importance of each category. If a Pareto effect exists, the cumulative line rises steeply for the first few defect types and then levels off. If the bars are almost linear, it is easy to analyze the slope of the cumulative percentage line.
Pareto Chart Example
Let’ s assume that you are a quality control manager of a concrete plant and you tested all the concrete samples. Concrete strength must be 30 Mpa and you categorized the results as per below table.
Number Of Sample Strength Category
In order to draw the cumulative percentage line you calculated the cummulative values as per below table.
Critical Very Important Important Less Important Unimportant
By using datas from the tables, you drawed The Pareto Chart shown below.
Benefits of The Pareto Analyses
The following are a few benefits of The Pareto Analyses:
– It enhances organizational efficiency
– It enhances problem solving skills
– It is visual presentation tool
– It can be prepared easily
– It improves decision making
Pareto Analysis is a valuable technique for making decisions in quality management. It is easy to use it for various purposes such as visualizing the importance of various categories, prioritizing the customer needs, analyzing the opportunities for investment etc.