# Robert Xiong's 5 whys Methodology

15. Apr 2016
1 von 10

### Robert Xiong's 5 whys Methodology

• 1. Determine the Root Cause - Five Whys & Robert Xiong’s Approach Robert Xiong May 29, 2014
• 2. What is the 5 Whys The 5-Whys 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. Invented by Japanese Industrialist Sakichi Toyoda, the idea is to keep asking “Why?” until the root cause is arrived at. 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. Very often the ostensible reason for a problem will lead you to another question. Although this technique is called “5 Whys,” you may find that you will need to ask the question fewer or more times than five before you find the issue related to a problem. Benefits of the 5 Whys • Help identify the root cause of a problem. • Determine the relationship between different root causes of a problem. • One of the simplest tools; easy to complete without statistical analysis. When Is 5 Whys Most Useful? • When problems involve human factors or interactions. • In day-to-day business life; can be used within or without a Six Sigma project.
• 3. How to Complete the 5 Whys 1.Write down the specific problem. Writing the issue helps you formalize the problem and describe it completely. It also helps a team focus on the same problem. 2.Ask Why the problem happens and write the answer down below the problem. 3.If the answer you just provided doesn’t identify the root cause of the problem that you wrote down in Step 1, ask Why again and write that answer down. 4.Loop back to step 3 until the team is in agreement that the problem’s root cause is identified. Again, this may take fewer or more times than five Whys. A key phrase to keep in mind in any 5 Why exercise is "people do not fail, processes do".
• 4. 5 Whys Worksheet Define the Problem: Why is that? 2. 1. 3. 4. 5. Action: Why is that? Why is that? Why is that? Caution: - If your last answer is something you can’t control, go back up to the previous answer - Cannot because of a person
• 5. 5 Whys Examples Problem Statement: Customers are unhappy because they are being shipped products that don’t meet their specifications. 1. Why are customers being shipped bad products? - Because manufacturing built the products to a specification that is different from what the customer and the sales person agreed to. 2. Why did manufacturing build the products to a different specification than that of sales? - Because the sales person expedites work on the shop floor by calling the head of manufacturing directly to begin work. An error happened when the specifications were being communicated or written down. 3. Why does the sales person call the head of manufacturing directly to start work instead of following the procedure established in the company? - Because the “start work” form requires the sales director’s approval before work can begin and slows the manufacturing process (or stops it when the director is out of the office). 4. Why does the form contain an approval for the sales director? - Because the sales director needs to be continually updated on sales for discussions with the CEO. In this case only four Whys were required to find out that a non-value added signature authority is helping to cause a process breakdown.
• 6. 5 Whys – Our Case Study Problem Statement: Astrios laser engine power dropped or changed during alignment or testing. 1. Why did the Astrios power drop? - Because the input end of the test fiber with the Astrios burned. 2. Why did the fiber input end burn? - Because the laser power came out of coupler higher than 15mW while aligning or peaking up the laser beam with the fiber. 3. Why did the laser power come out more than 15mW? - Because an ND filter was needed but was not put to reduce the power in 405nm laser path before the coupler. 4. Why was an ND filter needed but not put in the laser path? - Because there was no other way to control the laser power and there no warning sign or instruction to remind the technician to put an ND filter around the workstation. 5. Why wasn’t an instruction and warning sign available around the workstation? - Because the work instruction is not easy to access and the Traveler don’t have the warning words to remind the technicians. Action: ?
• 7. Phenomenon (Issue) Phenomenon 1 Phenomenon 2 (Symptom 1) Phenomenon 3 (Symptom 2) Phenomenon 4 (Symptom 3) … Symptom (Problem) Symptom 1 Symptom 2 (Cause 1) Symptom 3 Symptom 4 … Cause (Why) Cause 1 (Why) Cause 2 (Why) Cause 3 (Why) Cause 4 (Why) … Action Action 1 Action 2 Action 3 Action 4 … 5 Whys – Robert Xiong’s Approach
• 8. 5 Whys – Our Case Study Phenomenon (Issue) ILE power dropped or changed during alignment or testing. The output end of the fiber with the ILE burned. There were dusts on the fiber output end. The adapter connected to the fiber end for power measurement was dirty with dusts. There are dusts around the workstations. Symptom (Problem) The output end of the fiber with the ILE burned. There were dusts on the fiber output end. The adapter connected to the fiber end for power measurement was dirty with dusts. There are dusts around the workstations. The whole production area is open and no dust control is required. Cause (Why) There were dusts on the fiber output end. The adapter connected to the fiber end for power measurement was dirty with dusts. There are dusts around the workstations. The whole production area is open and no dust control is required. 1. Not that severe before? 2. Cost? 3. Budget? Action Clean and check the fiber ends before alignment or testing. Clean the adapter before connecting the fiber end to it. Clean the workstations daily. Make proper dust control/clean room criteria for the production. …
• 9. Take-away Quotation “If you don’t ask the right questions, you don’t get the right answers. A question asked in the right way often points to its own answer. Asking questions is the ABC of diagnosis. Only the inquiring mind solves problems.” – Edward Hodnett