#2. Invented by Japanese Industrialist Sakichi Toyoda, the idea is to keep asking “Why?” until the root cause is arrived at. The 5 Why method is simply asking the question “Why” enough times until you get past all the symptoms of a problem and down to the root cause. As customers become more experience in forcing suppliers to provide corrective action, they will request documentation that covers the 8D approach and 5Y analysis. And root cause for both occurrence and non-detection has to be addressed in 8D and necessary actions have to be taken to eliminate both of these root causes (Corrective action). They represent 8 steps to take to solve difficult, recurring or critical problems (often customer failures or major cost drivers). The 5 Why method is often used during the Analyze phase of the DMAIC process and the Plan phase of PDCA activities.
This article deals with the five why analysis. The structured approach provides transparency, drives a team approach, and increases the chance of solving the problem. 8D stands for the 8 disciplines of problem solving. The 5 Whys can be used individually or as a part of the fishbone (also known as the cause and effect or Ishikawa) diagram. 5-Why is a simple approach for exploring root causes and instilling a “Fix the root cause, not the symptom,” culture at all levels of a company. One applies the 5 why problem solving tool to determine the root cause of a problem. Once all inputs are established on the fishbone, you can use the 5 Whys technique to drill down to the root causes. The fishbone diagram helps you explore all potential or real causes that result in a single defect or failure. Final cause (Answer after asking last why) is the root cause. The eight disciplines (8D) model is a problem solving approach typically employed by quality engineers or other professionals, and is most commonly used by the automotive industry but has also been successfully applied in healthcare, retail, finance, government, and manufacturing.