The Lean Enterprise

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The Lean Enterprise

• Problem Solving - 5 Whys Approach

Lean Foundations Continuous Improvement Training
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Learning Objectives
The purpose of this module is to present the
definition of 5 why technique the benefits
5-why when 5 why is most useful. Review a
systematic example of 5 why.
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Identifying Root Cause

• 5 why is a problem solving technique that allows
  you to get at the root cause of a problem fairly
  quickly.
• It was made popular as part of the Toyota
  Production System (1970s.)
• Application of the strategy involves taking any
  problem and asking Why - what caused this
  problem?

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Identifying Root Cause

• By repeatedly asking the question "Why" (five is
  a good rule), you can peel away the layers of
  symptoms that can lead to the root cause of a
  problem. Very often the first reason for a
  problem will lead you to another question and
  then to another.
• Although this technique is called "5 Whys," you
  may find that you will need to ask the question
  fewer or more times than five before you find the
  issue related to a problem.

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Benefits

• It helps to quickly identify the root cause of a
  problem.
• It helps determine the relationship between
  different root causes of a problem.
• It can be learned quickly and doesn't require
  statistical analysis to be used.

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When is 5 whys most useful?

• When problems involve human factors or
  interactions.
• In all types of business situations whether
  solving a lean manufacturing or for any other
  business problem.

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Example of 5 why analysis

• Here is our "wheel" life example.
• Why is our largest customer unhappy? Because our
  deliveries of bicycles have been late for the
  last month.
• Why have our bicycle deliveries been late for the
  last month? Because production has been behind
  schedule.
• Why has production been behind schedule? Because
  there is a shortage of wheels.
• Why are we having a shortage of wheels? Because
  incoming inspection has rejected a large number
  of wheels for not being round.
• Why are we rejecting so many parts? Because
  purchasing switched to a cheaper wheel supplier
  that has inconsistent quality.
• Why

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Learn more at

• http//www.dwassoc.com/5-whys.php

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The Lean Enterprise

• Problem Solving - 5 Whys Approach

Lean Foundations Continuous Improvement Training