This presentation is one of a standard training series produced by the Goodrich Process Improvement organization at Charlotte Headquarters. The series has been prepared for use by Goodrich divisions in the training and continuing education of their personnel. Any use outside of Goodrich Corporation is expressly prohibited without the permission of Goodrich Process Improvement at Charlotte Headquarters. If you have any questions about this document or the training series, please contact Dave Anderson (704-423-6272, david.a.anderson@goodrich.com) or Al Mason (704-423-7569, al.mason@goodrich.com). Revision History: 0.0 20020402 Initial working draft prepared by Goodrich Process Improvement at Charlotte HQ 1.0 20020627 Initial production version released following comment period
Learning Objectives – at the conclusion of this presentation, students should be able to: Explain that root cause analyses are used to identify the basic errors that result in defects. Describe and/or demonstrate how the five whys are used to identify the root causes of problems. Delivery of this presentation requires approximately 10 minutes. Instructors can prepare handouts for students by printing the following slides: 1-8 (cut and paste numbers to the left into the “Slides:” text box in the “Print range” group of the “Print” dialogue).
After listing the forms of root cause analysis, instructor should point out that the bottom figure is a “fishbone diagram,” a framework for root cause analysis. When using the framework, the subject problem is written on the long horizontal line, immediate causes of that problem on the diagonal lines, secondary causes of the immediate causes on the smaller horizontal lines, etc. Fishbone diagrams allow investigators to identify the universe of factors that can lead to the subject problem, and then focus on the main ones.
Instructor should step through the five whys example with students. Instructor should point out that simple cause and effect analysis would have us replace the washing machine fuse after asking the first question.
Some students may point out that further whys are possible (“Why was the shaft seal missing?”). Instructor should point out that while further questions would help the washing machine manufacturing solve a potential process problem, they would not benefit this machine in particular. The depth of investigation, therefore, depends on the problem that you are trying to solve.
Question for students: “Why is root cause analysis so important?” Question for students: “Why five whys?”