Root Cause Analysis

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General summary of root-cause analysis (RCA) and some of the useful tools.

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Root Cause Analysis

  1. 1. Root-Cause Analysis (RCA) by Mark Fawcett
  2. 2. Contents <ul><li>RCA Assumptions </li></ul><ul><li>RCA Goals </li></ul><ul><li>Definitions of “Root Cause” </li></ul><ul><li>Levels of Causes </li></ul><ul><li>Practical Indicators of Root Cause </li></ul><ul><li>Cognitive Biases to Avoid </li></ul><ul><li>Seven-Step Problem-Solving Model </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  3. 3. RCA Assumptions <ul><li>“ Beneath every problem is a cause for that problem.” </li></ul><ul><li>“ If the root cause of a problem is not identified, then one is merely addressing the symptoms and the problem will continue to exist.” </li></ul><ul><li>(Doggett, 2005) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  4. 4. RCA Goals <ul><li>Identify . . . </li></ul><ul><li>What happened, </li></ul><ul><li>How it occurred, & </li></ul><ul><li>Why “it” took place. </li></ul><ul><li>What we can do to prevent reoccurrence </li></ul><ul><li>(Rooney & Heuvel, 2004) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  5. 5. Definitions of “Root Cause” <ul><li>For practical purposes, root causes are . . . </li></ul><ul><li>Specific underlying causes </li></ul><ul><li>Causes which we can reasonably identify </li></ul><ul><li>Causes that we have the ability to resolve </li></ul><ul><li>Causes where we can think of effective solutions to prevent recurrence </li></ul><ul><li>(Rooney & Heuvel, 2004) </li></ul><ul><li>“ Root-cause analysis is a thinking process that makes use of data from a variety of sources to identify the basic reason(s) for the appearance of a problem.” (Horev, 2009) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  6. 6. Levels of Causes <ul><li>Physical Cause: Specific physical item that, if corrected / replaced would fix problem. (aka proximal or direct cause) </li></ul><ul><li>System Cause: Possible underlying cause of physical failure. (aka distal / latent cause) </li></ul><ul><li>(Okes, 2008) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  7. 7. Levels of Causes — Example <ul><li>Physical Cause: Organizations have a tendency to stop at the physical cause, which may be appropriate. </li></ul><ul><li>System Cause: Seek system cause for problems with a high frequency, cost, or risk of injury. </li></ul><ul><li>(Okes, 2008) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  8. 8. Practical Indicators of Root Cause <ul><li>Can identify no deeper causal factors </li></ul><ul><li>All agree that the cause is a root cause </li></ul><ul><li>The cause provides clarity and appears to make sense </li></ul><ul><li>The cause is something you can influence </li></ul><ul><li>(Pruess, 2003) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  9. 9. Cognitive Biases to Avoid <ul><li>“ A biased mind, which never sees the complete picture, cannot grasp the reality.” — Dali Lama </li></ul><ul><li>Barriers to Effective RCA </li></ul><ul><ul><li>Cognitive Laziness: Instead of seeking the optimum result, we seek the first sufficient result. </li></ul></ul><ul><ul><li>Overconfidence: Pursuing evidence supporting our own beliefs rather than allowing the data to represent the truth. </li></ul></ul><ul><ul><li>(Okes, 2008) </li></ul></ul>Created by M. Fawcett Last Updated: 1/5/2010
  10. 10. Cognitive Laziness (Satisficing) <ul><li>Recency Bias </li></ul><ul><li>Assume the same cause for two recent problem symptoms and therefore, not performing a more rigorous investigation. </li></ul><ul><li>Availability Bias </li></ul><ul><li>Rely on the available data rather than collecting / generating more relevant and reliable data. </li></ul><ul><li>(Okes, 2008) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  11. 11. Overconfidence <ul><li>Anchoring Bias </li></ul><ul><li>Latching on to the first data and its indications while ignoring possibly conflicting evidence. </li></ul><ul><li>Confirmation Bias </li></ul><ul><li>Looking for and accepting only data the confirms our preexisting assumptions of the cause. </li></ul><ul><li>(Okes, 2008) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  12. 12. Seven-Step Problem-Solving Model Created by M. Fawcett Last Updated: 1/5/2010 (Westcott, 2006)
  13. 13. RCA Tools <ul><li>A few examples of RCA tool include . . . </li></ul><ul><li>Five “Why’s” (5Y) </li></ul><ul><li>Current Reality Tree (CRT) </li></ul><ul><li>Interrelationship Diagram (ID) </li></ul><ul><li>Cause-and-Effect Diagram (CED) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  14. 14. Five Why’s <ul><li>Simplest method to determine root cause. </li></ul><ul><li>Drill deeper into problems until a root cause is found. </li></ul><ul><li>(Boukendour & Brissaud, 2005) </li></ul><ul><li>Problem: Car will not start. </li></ul><ul><li>Why: Dead battery. </li></ul><ul><li>Why: Bad alternator. </li></ul><ul><li>Why: Alternator belt broken. </li></ul><ul><li>Why: Belt used beyond useful life. </li></ul><ul><li>Why: Recommend maintenance not performed. </li></ul><ul><li>(Wikipedia, 2009) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  15. 15. Five Why’s — Expanded Created by M. Fawcett Last Updated: 1/5/2010 (Westcott, 2006)
  16. 16. Current Reality Tree (CRT) <ul><li>Reflects most probable chain of causal factors contributing to a specific set of events. Aids in systems understanding. (Doggett, 2005) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  17. 17. Interrelationship Diagram (ID) <ul><li>Helps clarify mixed causal relationships of a complex problem. (Doggett, 2005) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  18. 18. Cause-and-Effect Diagram (CED) <ul><li>Sorts potential causes and organizes causal relationships. </li></ul><ul><li>Helps focus on problem content rather than history. </li></ul><ul><li>(Doggett, 2005) </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  19. 19. Conclusion <ul><li>System Causes: We should remember the difference between physical and system causes, understanding that solutions affecting the system causes provide more effective solutions. </li></ul><ul><li>Bias: We need to maintain our awareness of natural thinking biases, which can derail effective RCA. </li></ul><ul><li>7 Steps: Although many tools exist for RCA, we should adhere to the basic seven-step problem-solving model to ensure objective and effective solutions. </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  20. 20. Bibliography <ul><li>Boukendour, S., & Brissaud, D. (2005). A phenomenological taxonomy for systemizing knowledge on nonconformances. Quality Management Journal , 12(2), 25-33. </li></ul><ul><li>Doggett, A. M. (2005). Root cause analysis: A framework for tool selection. Quality Management Journal, 12 (4), 34-45. </li></ul><ul><li>Horev, M. (2009). How to succeed in failure analysis and fail in root-cause analysis. Electronic Device Failure Analysis, 11 (3), 14-19. </li></ul><ul><li>Hughes, B., Hall, M., & Rygaard, D. (2009). Using root-cause analysis to improve risk management. Professional Safety, 54 (2), 54-55. </li></ul><ul><li>Okes, D. (2008). The human side of root cause analysis. Journal for Quality & Participation, 31 (3), 20-29. </li></ul><ul><li>Pruess, P. G. (2003) School leaders guide to root cause analysis using data to dissolve problems. Larchmont, NY. Eye on Education. </li></ul><ul><li>Rooney, J. J. & Heuvel, L. N. V. (2004). Root cause analysis for beginners. Quality Progress, 37 (7), 45-53 </li></ul><ul><li>Westcott, R. T. (2006). The certified manager of quality/organizational excellence handbook (3rd ed.). Milwaukee, WI: ASQ. </li></ul><ul><li>Wikipedia. (2009). 5 Whys. Retrieved 1/5/2009 from http://en.wikipedia.org/wiki/5_Whys </li></ul>Created by M. Fawcett Last Updated: 1/5/2010
  21. 21. Questions / Discussion

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