Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Why why analysis

4,122 views

Published on

Techniques for root-cause analysis

Published in: Engineering
  • Be the first to comment

Why why analysis

  1. 1. Limited use: Only for Unilever For Unilever Internal Use Only WHY-WHY ANALYSIS PRESENTED BY: MD.FURKAN UDDIN JEWEL
  2. 2. Why-Why Analysis Why-Why AnalysisWhy-Why Analysis Why-Why Analysis is a technique for tracking down the root causes of undesirable phenomena logically and methodically, based on the facts, instead of merely brainstorming. Two Approaches in Why-Why AnalysisTwo Approaches in Why-Why Analysis - Approach starting from ‘what should have happened’- Think what the necessary conditions must be and list them up as items to investigate. Then investigate each condition on the spot to see whether it is actually being satisfied. - Approach starting from first principles- Focusing on the point at which the problem occurred, go back to first principles, and do the first step of the analysis by asking why these principles failed to operate. 8 Important Considerations when Implementing Why-Why Analysis8 Important Considerations when Implementing Why-Why Analysis 1) Clearly identify the phenomenon by closely observing the physical objects and materials involved 2) Use simple phrases like ‘A did/became B’ when defining the phenomenon and answering the Why?s 3) Check the logical structure of the analysis by reading back from the last Why? to the phenomenon. 4) Reading the analysis backward, check that all the possible causes have been identified for each event. 5) Continue asking Why? until you identify the actions that will prevent the problem from recurring. 6) Only note items that deviate from normal. 7) Avoid trying to identify causes lying in human psychology. 8) Do not use negative words such as ‘bad’. Click or Push Space bar
  3. 3. Why-Why Analysis Example Example: Hydraulic cylinder not working properly Why Because Action Why is the cylinder not working properly? Why did the holes in the strainer get clogged up? Why was the fluid dirty? Why did the dirt get inside the tank? Why did the lid have a hole in it, and not fit properly, leaving gaps around it? Because the holes in the strainer are clogged up. Because the hydraulic fluid was dirty. Because dirt had got inside the tank. Because the tank’s lid had a hole in it, and did not fit properly, leaving gaps around it. Because it was not maintained properly. Clean the strainer Remove the fluid and clean it. Prevent cutting debris and cutting fluid from flying around. Block the hole and make the lid fit properly, leaving no gaps. Standardise and train out the repair procedure. 1st Why? 2nd Why? 3rd Why? Phenomenon (result) Cause CausePhenomenon (result) CausePhenomenon (result) Phenomenon (result) Analysis continues until the final cause is found (often something to do with human behaviour) Click or Push Space bar
  4. 4. Limited use: Only for Unilever For Unilever Internal Use Only
  5. 5. Limited use: Only for Unilever For Unilever Internal Use Only
  6. 6. Limited use: Only for Unilever For Unilever Internal Use Only
  7. 7. Limited use: Only for Unilever For Unilever Internal Use Only

×