5why guideline
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This document outlines guidelines for conducting a 5-Why analysis to determine the root cause of problems. It discusses starting with a clear definition of the problem, considering all potential factors, answering "why" questions directly and without blame, continuing the questioning until reaching root causes, and logically linking the root causes back to the original problem. The purpose of 5-Why analysis is to understand underlying causes rather than symptoms so that effective countermeasures can be developed.
5why guideline
- 1. 5-Why Analysis §5-Why of Past 6 months (5 mins) Prepared by : DarrenTeh Date : 30th Jun 2004 §5-Why Revision (5 mins) Agenda §Conclusion (10 mins) §Guideline of Asking Why Why Why (20mins) §Case study 1 & Presentation (90 mins) §5-Why Judgment Matrix (15 mins) §Case Study 2 & Presentation (75 mins)
- 2. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Revision -- Purpose Started popular since 1970s’ suggested by Mr. Masaaki Imai (Toyota) as a trouble shooting technique. To find the root causes of a problem or defect by carefully and repeatedly asking “Why”. Once root cause is understood, countermeasure can then be developed and implemented effectively.
- 3. ‚ PDS TATUS & I MMEDI AT ACTION OF PROBLEM 1.1@STATU 1.2 IMMEDIATE ACTION<Inspection/Selection/Others> ¦ ‚ RDI NVES TI GA TION ON CAUS E OF OCCUR R ENC E COUNTERMEASURE ¦ ‚ SDI NVES TI GA TION ON CAUS E OF OUT F LOW COUNTERMEASURE ¦ ‚ TDCONF I RMA TION COUNTERMEASURE EFFECTIVENESSCAUSECOUNTERMEASURE 3rd W H Y 4th W H Y F A C T 1st W H Y 2nd W H Y CAUSECOUNTERMEASURE 5th W H Y OCCURRENCE OUTFLOW FO O L PRO O F; YES or NO STANDARDIZATIO N ;NEED or NO T (SCHEDULE : XXXX/*** ) FO O L PRO O F; YES or NO STANDARDIZATIO N ;NEED or NO T ¦ ‚ QDGRAS P OF THE Fi St at us of pr oducts quality/Analysis of factor 2-1 Investigation of defective products 2-2 Investigation of process( Rule vs Actual) / Analysis of factor 6.1 HORIZONTAL DEPLOYMENT 6.2 STANDARDIZATION ¦ ‚ UDHOR I ZONT DEPLOYMENT & STANDARDIZATION 1 1 2 3 3 4 5 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Revision -- 5-Why Analysis Report
- 4. YES NO Remarks 1.1 Defective quantity at customer or occurrence site. 1.2 Defective quantity at Warehouse, Supplier or on shipment. 1.3 Rejected ratio, frequency of occurrence. 1.4 What is the consequence on function ability? 1.5 When / Where does defective happened? ( Lot No., Serial No., Production Date, etc. ) 1.6 How the defect being detected? Any special condition? 1.7 Investigation of actual parts, confirmation on the defect ( compare with specification ). 2.1 What is the defect? How far deviated from specification? ( Minimum / Maximum / Average ) 2.2 Confirmation on Quality Requirement / Standard. ( Data collection of production records, inspection check sheets, etc. ) 2.3 Suspected causes from above finding. 2.4 Thorough investigation on the suspected causes. 2.5 Possible to confirm the root cause? (Re-occurrence test? ) 2.6 Are followings being considered? Why if any following data is not available, insufficient or deviated from quality standard? Human factor and if training is effectively carried out? Record of process parameter, inspection check list? Any pro-active action if any abnormality? Machinery / equipment condition? Any machine check list or maintenance? Any change in material, source, dimension, etc.? 2.7 If any of above deviated from specification or standard, why is it happened? Are there any imperfect on the operations system? 3.1 Any immediate counter-measure to prevent further outflow? 3.2 Is the counter-measure react to the root cause of both occurrence and outflow? 3 CAUSE AND 3.3 Considering all possible counter-measures to solve the problem. COUNTER-MEASURE 3.4 Counter-measure on Technical / Engineering matter. 3.5 Counter-measure on Quality System. 3.6 Counter-measure on daily management. 3.7 Consider all 4M on the counter-measure. 3.8 Pokayoke 4.1 It will not resolve one defect but create another defect. 4 COUNTER-MEASURE 4.2 Monitoring of re-occurrence. EFFECTIVENESS 4.3 To confirm the possibility of re-occurrence. 4.4 To establish measurable judgement of counter-measure. 4.5 Relevant personnel well understand on the rational of counter-measure. 5.1 Sufficient training on relevant personnel. 5 HORIZONTAL 5.2 Relevant personnel well understand the 5-Why Analysis. DEPLOYMENT 5.3 Able to apply onto other models / products. 5.4 Able to apply onto other operations. STATUS OF PROBLEM1 2 GRASP OF THE FACT CATEGORY CHECK POINTS 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Revision -- General Checklist
- 5. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 5-Why Analysis Report from Fronts in Past 6 Months Fronts No. of 5-Why Report Submitted SAM 1 STC 2 SIT 2 ISI 2 SVL 3 SPK
- 6. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 5-Why Analysis Report from Fronts in Past 6 Months 1) Status of problem 2) Fact (why-why) 3) Causes & countermeasures 4) Effectiveness 5) Deployment
- 7. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … 1) Get Start on 1st Why 2) Answering 3) Chain of Whys & Answers 4) Where End ? 5) Reversal
- 8. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (1) Get Start on 1st Why To ask Why did this defect or problem occur? And Why defective yet outflow to customer. (A) Start asking Why only after thorough investigation on occurrence of defect. To first investigate what type of noise, where noisy, how noisy, when noisy… before ask why ! Example 1: Why compressor noisy? NG
- 9. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (1) Get Start on 1st Why (B) Write down the specific problem, writing the issue helps you formalize the problem. Ask the right question ! (If you do not ask the right question, you don’t get the right answer. Example 2: Claim on compressor bracket crack, and found one bolt has been broken. Why compressor bracket bolt broken? Why compressor bracket is cracked?
- 10. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (2) Answering (A) Answer direct to point. Example 1: Why Dimension NG but out flow to customer? Because only sample inspection, cannot detect all defective part. Firstly, manufacturing must ensure dimension within spec., such as Cpk >1.33. So find out what’s wrong there, but not sampling inspection. NG
- 11. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (2) Answering (B) Consider 4M DIE LEG BROKEN MATERIALMACHINE MAN METHOD HANDLING PROCESS ATTITUDE Insufficient TRAININ G Poor/ Bad IN - EXPERIENCE New operator Moulding M/C Life Span Poor Control MANPOWER High turn over BEAD Size Loading/ Unloading Improper Platform Too High Chute Staking Too High Too Steep Erosio n Maintenance Poor Poor Life Span Control CAUSE & EFFECT DIAGRAM - STYROFOAM PREPARED BY : ALFRED TAN TAY BOON CHEI DATE : 02OCTOBER2001 DISCUSSION WITH BW (60 MINS) MEMBERS: Ms SUSAN (BROADWAY) ALFRED/TAY B C (SIS-QD) Incorrect Spec/Grade Incorrect Poor Maintenanc e Steam Pressure Control PRE- EXPANSION Density Control Weighing NG Wrong Wrong Die Design Weak at leg porting ENVIRONMENT Practice Double Handling Poor Fusion Packing Too Heavy
- 12. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (2) Answering (C) Steer away from blaming individuals. Blaming individual people leaves you with no option except to punish them, and this leaves no room for substantive change. The question is “Why?”, not “Who”.
- 13. Prepared by : DarrenTeh Date : 30th Jun 2004 When previous answer is found, ask “Why is this the case?” again and again…like peeling away the layers of symptoms which can lead to the root cause. 5-Why Analysis Guidelines on Why Why Why … (3) Chain of Whys
- 14. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (3) Chain of Whys (A) As each answer is recorded, ask: “OK, is it the only answer ?” 1st Why 2nd Why 1st Answer 2nd Why 1st Answer 3rd Why 2nd Answer 3rd Why 2nd Answer 3rd Why 2nd Answer 4th Why 3rd Answer 4th Why 3rd Answer 4th Why 3rd Answer 4th Why 3rd Answer 5th Why 4th Answer 5th Why 4th Answer 5th Why 4th Answer 5th Why 4th Answer 5th Answer 5th Answer 5th Answer 5th Answer
- 15. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (3) Chain of Whys 1st Why 2nd Why 1st Answer 2nd Why 1st Answer 3rd Why 2nd Answer 3rd Why 2nd Answer 3rd Why 2nd Answer 4th Why 3rd Answer 4th Why 3rd Answer 4th Why 3rd Answer 4th Why 3rd Answer 5th Why 4th Answer 5th Why 4th Answer 5th Why 4th Answer 5th Why 4th Answer 5th Answer 5th Answer 5th Answer 5th Answer (A) As each answer is recorded, ask: “OK, is it the only answer ?”
- 16. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (3) Chain of Whys Example 1: The floor near the machine is oily. 1st Why the floor near machine is oily? Because oil leak out from machine. 2nd Why oil leak out from machine? Because one valve is leakage. 3rd Why the valve is leakage? Because the seal has been worn out? 4th Why the seal has been worn out? Because…..design, maintenance, etc Event System (B) Develop the answer from Event-oriented to systematic explanation. (From symptom to cause.)
- 17. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (4) Where End? The causes that countermeasure can be taken place and defect/problem will be eliminated effectively with no possibility of re-occurrence.
- 18. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (A) Root cause should not be taken to mean the last link in the chain of Whys. It should mean the network of things (below the surface) that taken together produced the problem (on the surface), i.e. after it reaches the level of systematic explanation. (4) Where End?
- 19. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … 1st Why did your car breakdown on the road? Because run out of petrol 2nd Why did it run out of petrol? Because I didn’t buy petrol before used up 3rd Why didn’t you buy the petrol before used up? Because I have not money 4th Why didn’t you have any money? Because I just lost it all in casino 5th Why you lost it all in casino? Example 1 : Car Break Down on Road Problem lies on his personality, countermeasure to be done on his attitude. (4) Where End? Because my skill of gamble is poor… Because I make mistake… Because I have not enough money to win back… Similarly, asking whysss on a technical defect will often reveal the imperfect of working system or management that needed improvement.
- 20. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (B) Continue question and answer until not able to provide straight forward answer. Asking “Why” and answering “Why carefully until a “Cause Unknown” is surfaced. When the answer is “I don’t know”, then you have a “Why” whose cause is unknown, then it should be the cause to take effective action. (4) Where End?
- 21. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (5) Reserval Defective Why 1? Why 2?Answer 1 Root Cause Why 3? Why 5? Why 4? Answer 4 Answer 3 Answer 2
- 22. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … (5) Reserval Defective Root CauseIf so, then… If so, then… Answer 4 If so, then… If so, then… Answer 1 If so, then…Answer 3 Answer 2 Must be logically link back from Root Cause to Defective.
- 23. 5-Why Analysis Prepared by : DarrenTeh Date : 30th Jun 2004 Guidelines on Why Why Why … Summary Get start on 1st Why (A) Only carry out after thorough investigation on occurrence of defect. (B) Writing the issue helps you formalize the problem. Answering (A) Answer direct to point. (B) 4M (C) Steer away from blaming individuals. Chain of 5-Why & Answer (A) Is it the only answer? (B) Develop the answer from Event-oriented to systematic explanation. (From symptom to cause.) Where End? Until Root Causes revealed (A) Things (below the surface) that taken together produced the problem (on the surface). (B) Continue question and answer until not able to provide straight forward answer. Reversal (A) Reverse from root cause, “if so.. then” that logically return to the defect.