5 WHY Analysis, a TPM Tool for Root Cause Analysis (RCA)

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Section 1

5 WHY Process

Causes of Losses are Often Complicated:

Common Failure scenario:

1. Management system breakdown
2. Failure to implement counter-measures
3. Premature equipment failure
4. Employees fails to follow procedure
5. Failure to ID & Respond
6. Large Loss Results

5 Why Analysis is Proactive Addresses the Underlying Causes of Losses:

  • 5 Why identifies the Root Causes of Losses
  • Supports Implementation of Countermeasures
  • Promotes Transfer of Learning

Where Does 5 WHY Fit in the Focused Improvement Process?

Focused Improvement Process

  1. Collect Data
  2. Identify, Prioritize & Select Projects.
  3. Ensure Equipment Is Restored
  4. Establish the Team
  5. Use the CAP-Do Process (5 Why is used here)…….. to manage improvement cycle
  6. Monitor and Hold the Gains
  7. Document the Project (Kaizen Summary Sheet, Kaizen dbase)
  8. Celebrate Success
  9. Replicate Where Applicable.
  10. Share Learnings (Kaizen database, CI and Pillar CoP’s )

How is 5 WHY used in CAP-Do ?

1. CHECK

a. Identify the problem

b. Understand the Ideal Situation

  1. Machine: equipment sketches and the operational principle
  2. Material: samples of material involved in the problem
  3. Method: Flow charts of the process
  4. Man: Forms, procedures

c. Identify the Phenomenon 5W1H Analysis

2. ANALYZE

Root Cause Analysis tools: 5 WHY

3. PLAN

a. Action Plans (Immediate, Intermediate, Long Term)

4. DO

  1. Safety Comes First!
  2. OPL’s
  3. Implement Actions
  4. Observe Results & Hold the Gains

Before Starting a 5 WHY ANALYSIS …

  • The CHECK phase of CAP-Do must be completed . . .

– The problem identified

– The Ideal Situation understood

– The Phenomenon identified through the 5W 1H Analysis

 

How Do You Start the 5 WHY Analysis once you identify the Phenomenon (5W 1H Analysis) ?

  • The 5 WHY Analysis involves asking the question “WHY ?” multiple times (typically 5) until you arrive at the root cause.
  • The Phenomenon Statement from the 5W1H is the starting point for the first WHY.

EXAMPLE (see picture above) – Transition from 5W1H (CHECK Phase) to 5 WHY (ANALYZE Phase)

  • Why does Line X Capper experience spills at the entrance after changeover to 475 ml?

Ask Why…? Ask Successive Whys…?

(Follow Phenomenon – (Be)Cause Relationship)

 

Develop a Cause Tree to Order your Thinking

 

5 WHY Analysis Using the 4 M’s

 

Causes to Consider: 

Equipment Branch (Machine)

  • Improper Equipment Ordered
  • Poorly Designed Equipment
  • Inadequate Maintenance
  • Wear & Tear
  • Abuse or Misuse

Materials Branch (Material)

  • Materials out of spec:
  • Product
  • Packaging
  • Ingredients
  • Materials damaged:
  • by machine
  • from storage
  • from supplier

Procedural (Method)

  • Lack of Procedures
  • Inadequate Procedures
  • Misunderstood Procedures
  • Failure to Warn or Respond
    Note: Large losses often occur because of failure to take timely action

Behavioral Branch (Man)

  • Lack of Knowledge
  • Lack of Skill
  • Physically Incapable
  • Lack of Motivation

5 Why Analysis Pitfalls to Avoid

  • Failure to step SLOWLY and METHODICALLY through the process
  • Tendency to jump several “Why”s at once
  • Tendency to assign pre-conceived causes
  • Failure to consider ALL of the causes
  • Use 4-M approach to help avoid this pitfall

5 Why Analysis – Recommendations

What to do with the Recommendations?
. .
.Follow CAP-Do . . .

How to go from 5 Why to the PLAN Phase of CAP-Do?

  1. For each of the last Why answers, identify recommendation(s) (countermeasures):

  1. Develop an Action Plan for each of the countermeasures:

Carry Out “Do” Phase of CAP-Do

Implement the Action Plan

Hold the Gains by Developing Standards:

  • Cleaning, Inspection & Lubrication Standards
  • Processing Standards
  • Maintenance Standards
  • Training Standards (i.e. One Point Lessons)
  • Engineering Standards

One Point Lesson

Section 2. Application of the 5 WHY Process

The Loss  Pyramid

Application of 5 Why
Enables Identification of Problems BEFORE They Escalate Up the Pyramid

  • Identifying Sources of Contamination, Stoppages (AM Pillar)
  • Tool for Analyzing Cause / Losses in Focused Improvement (FI Pillar)
  • ID Reasons for Breakdowns (EM Pillar)
  • ID Causes of Minor Defects, Out of Spec
    (QM Pillar)
  • ID Causes of Near Misses, First Aids (SHE Pillar)

Section 3 Field Case Studies

Root cause analysis

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