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#8 Root Cause Analysis

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suman_purumandla

The document discusses root cause analysis techniques for problem solving. It addresses key questions about when action should be taken to address problems and the importance of treating each problem seriously to find the underlying cause. Various tools for root cause analysis are defined, including brainstorming, cause-and-effect diagrams, the 5 whys technique, checklists and flowcharts. Guidance is provided on effective use of cause-and-effect diagrams and 5 whys to delve beyond symptoms and uncover root causes.

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Root Cause Analysis
Group Discussion Addressing the Key Points of Root Cause Analysis Question 2: Is action dependent on the cost of the part? Question 3: Why is it important to treat each problem like a Golden Nugget? Question 4: Is best-in-class or simply beating your competitor’s quality levels good enough? Question 1: How many times does the same problem have to occur before action is taken?
Problem Escapes and the Rule of 10 Defect Found at: Cost to the Company: Impact to the Company: Own Process Very Minor Next Process Minor Delay End of Line Rework Reschedule of Work Final Inspection Significant Rework Delay in Delivery Additional Inspection Customer Warranty Cost Admin. Cost Reputation Loss of Market Share $1 $10 $100 $1,000 $10,000
The “True” Problem Must Be Understood Before Action Is Taken (cont.) Without using data to find the “true problem,” we suffer the consequences of: Addressing the wrong problem The “quick fix” Unsatisfied customers Wasted resources Increased frustration Never really solving the problem Creating more problems
Symptom Approach vs. Root Cause Symptom Assumes at any given time a worker makes a choice to work error-free or not. Root Cause Assumes that errors are the result of defects in the process. People are only part of the process. Addressing the Wrong Problem “ Old Mindset” “ New Mindset” Assumes errors are the result of worker carelessness. Assumes that there are multiple causes for errors. The method for improvement is to motivate workers to be more careful. The method for improvement involves identifying appropriate ways to improve the process.
Philosophy of Root Cause Methodology Each problem is a golden nugget or treasure. Each problem tells a story about why and how it occurred. (There are no isolated incidents.) Solving problems requires a mindset that is alert, open-minded, patient, tenacious, and persistent. It is critical that everyone take a personal and active role in improving quality. The “true” problem must be understood from the data before action is taken. Each problem must be pursued and resolved rapidly. Fundamental Elements
Root Cause Analysis Definition Rapid and persistent pursuit of the fundamental breakdown or failure of the process that, when resolved, prevents a recurrence of the problem.
Process Definition The combination of people, material, machines, tools, environment, preventive maintenance, measuring and test equipment, and work instructions necessary to produce a product or service.
Root Cause Tools Brainstorming Force field analysis Team forming 5 Why’s Histogram Pareto charts Solution selection diagrams Nominal group technique Storyboarding Solution Selection diagrams Generating Ideas Prioritizing Data or Action Action Planning Cause and effect diagram Scatter diagram Failure mode and effect analysis Event tree analysis Force field analysis Guide for data collection Statistical Engineering Check sheet Run chart QCPC Storyboarding Function analysis Control chart Process analysis The 5 Why’s PDCA (Plan-Do-Check-Act) Finding Patterns and Relationships Examining Results Grouping Ideas Nominal group technique Process analysis Root cause test Duplication of failure (i.e.: Red X)
Brainstorming Guidelines Clearly define the problem Collect ideas Record all ideas Freewheeling of ideas encouraged No judgment (pro or con) Clarify and combine Clarify each idea individually Prioritize Identify the ideas that best meet the requirements
The purpose is to understand: The key sources that contribute most significantly to the problem The relationship among the wide variety of possible contributors Cause-and-Effect Diagram
or Fishbone or Ishikawa Diagram Cause-and-Effect Diagram Other (on every diagram) Causes Effect Materials Machinery Policies Plant/Equipment People Procedures Effect Man/Woman Methods Problem Reason Counter Measure
Cause-and-Effect Diagram Eliminated symmetry, added notch Materials Machinery Man/Woman Methods Cannot Load Software on PC Power Interruption Bad Disk Diskette Missing Wrong Type Disk Don’t Have Mouse Inserted Disk Wrong Instructions Are Wrong Not Following Instructions Cannot Answer Prompt Question Graphics Board Incompatible Other Instructions Were Not Clear Not Enough Free Memory Hard Disk Crashed Upside Down Backward
Tips for effective Cause-and-Effect Diagrams Review all candidate problems (Effects) and eliminate or combine duplicates. Clearly identify the “Effect” which you are trying to eliminate. Brainstorm the various causes for the “Effect”. Resist the temptation to state solutions before all the causes are identified. Challenge ideas as to whether they are a “Cause” of “Effect”. Insure that the “Causes” identified are process variables not special causes.
Tips for effective Cause-and-Effect Diagrams Prioritize the most likely causes. Take special note of causes that appear repeatedly. Keep asking “Why?” until you get to the root of the problem. Plan at least (2) counter measures to prevent recurrence.
5 Why’s A questioning technique for getting beyond symptoms and uncovering root causes.
5 Why’s (cont.) What’s happening that shouldn’t be? Why is it happening? Problem 1 2 3 4 5 Why is that? Why is that? Why is that? Why is that? C A U S ES Caution: If your last answer is something you cannot control, go back to previous answer
Problem Why? Corrective Action Flat Tire in Garage Nails on garage floor Swept up nails Example: 5 Why’s
Problem Why? Why? Why? Why? Why? Flat Tire in Garage Nails on garage floor Box on shelf split Box got wet Rain through hole in garage roof Rain happens Example: 5 Why’s
Keys to Success Question everything Do not stop until you are down to causes that can be tested and attacked Ask, “why, why, why?” until you know the fundamental element of the process that failed Ask the experts—the users of the process Get other outside help Neutral More objective Be patient in your pursuit

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#8 Root Cause Analysis

  • 2. Group Discussion Addressing the Key Points of Root Cause Analysis Question 2: Is action dependent on the cost of the part? Question 3: Why is it important to treat each problem like a Golden Nugget? Question 4: Is best-in-class or simply beating your competitor’s quality levels good enough? Question 1: How many times does the same problem have to occur before action is taken?
  • 3. Problem Escapes and the Rule of 10 Defect Found at: Cost to the Company: Impact to the Company: Own Process Very Minor Next Process Minor Delay End of Line Rework Reschedule of Work Final Inspection Significant Rework Delay in Delivery Additional Inspection Customer Warranty Cost Admin. Cost Reputation Loss of Market Share $1 $10 $100 $1,000 $10,000
  • 4. The “True” Problem Must Be Understood Before Action Is Taken (cont.) Without using data to find the “true problem,” we suffer the consequences of: Addressing the wrong problem The “quick fix” Unsatisfied customers Wasted resources Increased frustration Never really solving the problem Creating more problems
  • 5. Symptom Approach vs. Root Cause Symptom Assumes at any given time a worker makes a choice to work error-free or not. Root Cause Assumes that errors are the result of defects in the process. People are only part of the process. Addressing the Wrong Problem “ Old Mindset” “ New Mindset” Assumes errors are the result of worker carelessness. Assumes that there are multiple causes for errors. The method for improvement is to motivate workers to be more careful. The method for improvement involves identifying appropriate ways to improve the process.
  • 6. Philosophy of Root Cause Methodology Each problem is a golden nugget or treasure. Each problem tells a story about why and how it occurred. (There are no isolated incidents.) Solving problems requires a mindset that is alert, open-minded, patient, tenacious, and persistent. It is critical that everyone take a personal and active role in improving quality. The “true” problem must be understood from the data before action is taken. Each problem must be pursued and resolved rapidly. Fundamental Elements
  • 7. Root Cause Analysis Definition Rapid and persistent pursuit of the fundamental breakdown or failure of the process that, when resolved, prevents a recurrence of the problem.
  • 8. Process Definition The combination of people, material, machines, tools, environment, preventive maintenance, measuring and test equipment, and work instructions necessary to produce a product or service.
  • 9. Root Cause Tools Brainstorming Force field analysis Team forming 5 Why’s Histogram Pareto charts Solution selection diagrams Nominal group technique Storyboarding Solution Selection diagrams Generating Ideas Prioritizing Data or Action Action Planning Cause and effect diagram Scatter diagram Failure mode and effect analysis Event tree analysis Force field analysis Guide for data collection Statistical Engineering Check sheet Run chart QCPC Storyboarding Function analysis Control chart Process analysis The 5 Why’s PDCA (Plan-Do-Check-Act) Finding Patterns and Relationships Examining Results Grouping Ideas Nominal group technique Process analysis Root cause test Duplication of failure (i.e.: Red X)
  • 10. Brainstorming Guidelines Clearly define the problem Collect ideas Record all ideas Freewheeling of ideas encouraged No judgment (pro or con) Clarify and combine Clarify each idea individually Prioritize Identify the ideas that best meet the requirements
  • 11. The purpose is to understand: The key sources that contribute most significantly to the problem The relationship among the wide variety of possible contributors Cause-and-Effect Diagram
  • 12. or Fishbone or Ishikawa Diagram Cause-and-Effect Diagram Other (on every diagram) Causes Effect Materials Machinery Policies Plant/Equipment People Procedures Effect Man/Woman Methods Problem Reason Counter Measure
  • 13. Cause-and-Effect Diagram Eliminated symmetry, added notch Materials Machinery Man/Woman Methods Cannot Load Software on PC Power Interruption Bad Disk Diskette Missing Wrong Type Disk Don’t Have Mouse Inserted Disk Wrong Instructions Are Wrong Not Following Instructions Cannot Answer Prompt Question Graphics Board Incompatible Other Instructions Were Not Clear Not Enough Free Memory Hard Disk Crashed Upside Down Backward
  • 14. Tips for effective Cause-and-Effect Diagrams Review all candidate problems (Effects) and eliminate or combine duplicates. Clearly identify the “Effect” which you are trying to eliminate. Brainstorm the various causes for the “Effect”. Resist the temptation to state solutions before all the causes are identified. Challenge ideas as to whether they are a “Cause” of “Effect”. Insure that the “Causes” identified are process variables not special causes.
  • 15. Tips for effective Cause-and-Effect Diagrams Prioritize the most likely causes. Take special note of causes that appear repeatedly. Keep asking “Why?” until you get to the root of the problem. Plan at least (2) counter measures to prevent recurrence.
  • 16. 5 Why’s A questioning technique for getting beyond symptoms and uncovering root causes.
  • 17. 5 Why’s (cont.) What’s happening that shouldn’t be? Why is it happening? Problem 1 2 3 4 5 Why is that? Why is that? Why is that? Why is that? C A U S ES Caution: If your last answer is something you cannot control, go back to previous answer
  • 18. Problem Why? Corrective Action Flat Tire in Garage Nails on garage floor Swept up nails Example: 5 Why’s
  • 19. Problem Why? Why? Why? Why? Why? Flat Tire in Garage Nails on garage floor Box on shelf split Box got wet Rain through hole in garage roof Rain happens Example: 5 Why’s
  • 20. Keys to Success Question everything Do not stop until you are down to causes that can be tested and attacked Ask, “why, why, why?” until you know the fundamental element of the process that failed Ask the experts—the users of the process Get other outside help Neutral More objective Be patient in your pursuit