Root cause analysis (RCA) is one of the most important elements of problem-solving in quality management.
That’s because if you’re not aiming at the right target, you’ll never be able to eliminate the real problem that’s hurting quality.
Fortunately for manufacturers, there is a wide range of root cause analysis tools available today, which vary with the situation.
The Pareto chart, for example, is a histogram or bar chart combined with a line graph that groups the frequency or cost of different problems to show their relative significance. The bars show frequency in descending order, while the line shows cumulative percentage or total as you move from left to right.
Layered process audits (LPAs) allow you to check high-risk processes daily to verify conformance to standards. LPAs identify process variations that cause defects, making Pareto charts a powerful reporting tool for analyzing LPA findings.
Pareto charts are one of the seven basic tools of quality described by quality pioneer Joseph Juran. Pareto charts are based on Pareto’s law, also called the 80/20 rule, which says that 20% of inputs drive 80% of results.
The scatter plot (or scatter diagram) is another popular root cause analysis tool that uses pairs of data points to help uncover relationships between variables. A scatter plot is a quantitative method for determining whether two variables are correlated, such as testing potential causes identified in your fishbone diagram.
Making a scatter diagram is as simple as plotting your independent variable (or suspected cause) on the x-axis, and your dependent variable (the effect) on the y-axis. If the pattern shows a clear line or curve, you know the variables are correlated and you can proceed to regression or correlation analysis.
Want to learn more? Tonex offers nearly three dozen courses in Root Cause Analysis Training. Some of our classes include:
For more information, questions, comments, contact us.