HISTORY 5 Why? The technique was originally developed by Sakichi Toyoda and was used within the Toyota Motor Corporation during the evolution of its manufacturing methodologies. It is a critical component of problem-solving training, delivered as part of the induction into the Toyota Production System. The architect of the Toyota Production System, Taiichi Ohno, described the 5 Whys method as "the basis of Toyota's scientific approach . . . by repeating why five times, the nature of the problem as well as its solution becomes clear. 5 Why? SIX SIGMA Six Sigma is a disciplined, data-driven approach and methodology for eliminating defects (driving toward six standard deviations between the mean and the nearest specification limit) in any process – from manufacturing to transactional and from product to service. The 6th “S” is for Safety. The 5 Whys is a technique used in the Analyze phase of the Six Sigma DMAIC (Define, Measure, Analyze, Improve, Control) methodology. ... By repeatedly asking the question “Why” (five is a good rule of thumb), you can peel away the layers of symptoms which can lead to the root cause of a problem. Rules of performing 5 Whys 1. It is necessary to engage the management in the 5Whys process in the company. For the analysis itself, consider what is the right working group. Also consider bringing in a facilitator for more difficult topics. 2. Use paper or whiteboard instead of computers. 3. Write down the problem and make sure that all people understand it. Rules of performing 5 Whys (continued) 4. Distinguish causes from symptoms. a. The difference between a cause and a symptom is that a cause is usually the result of a decision, whereas a symptom is the director or indirect result of a cause. b. For example, if a business decides to acquire another business then all the subsequent consequences are symptoms of that decision. The cause is the original decision. Cause is a person or thing or event that gives rise to an action while a symptom is as a result of a cause. Rules of performing 5 Whys (continued) 5. Pay attention to the logic of cause-and-effect relationship. 6. Make sure that root causes certainly lead to the mistake by reversing the sentences created as a result of the analysis with the use of the expression "and therefore". 7. Try to make our answers more precise. 8. Look for the cause step by step. Don't jump to conclusions. 9. Base our statements on facts and knowledge. 10. Assess the process, not people. Rules of performing 5 Whys (continued) 11. Never leave "human error", "worker's inattention", "blame John" etc., as the root cause. 12.Foster an atmosphere of trust and sincerity. 13.Ask the question "Why" until the root cause is determined, i.e. the cause the elimination of which will prevent the error from occurring again. 14.When you form the answer for question "Why" - it should happen from the customer's point of view. EXAMPLE EXAMPLE The vehicle will not start. (the problem) 1. Why? - The battery is dead. (First why) 2. Why? - The alternator is not functioning. (Second why) 3. Why? - The alternator belt has broken. (Third why) 4. Why? - The alternator belt was well beyond its useful service life and not replaced. (Fourth why) 5. Why? - The vehicle was not maintained according to the recommended service schedule. (Fifth why, a root cause) Tools and equipment-Not trained Tools and equipment-Unsuitable Tools and equipment-Unavailable Tools and equipment-Defective PPE-Not adequate ROOT CAUSES PPE-Not issued (my standard list) PPE-Not used Work methods-Bad Practice Work methods-Accepted Practice Work methods-Lack of Standard Instruction-Not Provided Instruction-JHA not under taken Instruction-Not specific enough Instruction-Working outside of capabilities Work Environment- Hazard Not Identified Work Environment-Hazard not mitigated Work Environment-Not trained to deal with hazards 5 Why? “To understand the reasons you must first look at the origins” END Victor DiOrio Dior LTD
