If the solution is not obvious, even after a Pareto analysis has narrowed the search, two additional techniques that can be helpful are brainstorming and fishbone diagrams. In a brainstorming session, a group is assembled and members suggest possible causes of the problem, calling out their ideas either randomly or each in turn. Censorship is not allowed, and every idea, no matter how bizarre, is written down. One member of the group records the possible causes, usually on a whiteboard or flipchart, where they are used as a springboard for additional ideas. After the group has run out of ideas, group members discuss and prioritize the list.
Fishbone diagrams are another method for identifying problem causes.
Using data obtained from the Pareto, brainstorming, and fishbone tools, you should be able to identify what has changed in your process. Though there are others, these are the primary SPC tools that have been developed by quality practitioners over time. By using the right tool in the right situation, a superior quality department will be able to identify and remediate the root cause of a problem quickly and efficiently. Select another article. Return to Quality Magazine's home page.