Problem Solution - 5 Why's Analysis
5 whys as part of lean manufacturing 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 (1970’s.) Application of the strategy involves taking any problem and asking “Why - what caused this problem?”
Benefits Of The 5 Whys.
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.
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.
Example of a five Why Analysis. ...Here is our "wheel" life example.
1. Why is our largest customer unhappy? Because our deliveries of bicycles have been late for the last month.
2. Why have our bicycle deliveries been late for the last month? Because production has been behind schedule.
3. Why has production been behind schedule? Because there is a shortage of wheels.
4. Why are we having a shortage of wheels? Because incoming inspection has rejected a large number of wheels for not being
round.
5. Why are we rejecting so many parts? Because purchasing switched to a cheaper wheel supplier that has inconsistent quality.

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Problem Solution - 5 Why's Analysis Worksheet
Part Number:
Date:
Area:
Product/Process:
Problem Description:
Use this route to specify the nonconformity that is being investigated.
Root Causes
Corrective Action &
Therefore
Responsibility
Date
Why?
A
Therefore
Why?
Therefore
Why?
Therefore
A
Use this route to investigate why
Why?
the problem wasn’t detected
Therefore
Why?
Therefore
Why?
Why?
B
Therefore
Why?
Therefore
Why?
Therefore
B
Use this route to investigate the
Why?
root cause of the system.
Therefore
Why?
Therefore
Why?
Why?
C
Therefore
Why?
Therefore
Why?
Therefore
C
Why?
Therefore
Why?
Why?
Problem Solution Completed:
Solution Date:
Break point of the change in the process:
Implementation Date:

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Fishbone
Root Cause Identification Tool
(complete for product involved in quality issue)
Machine
Material
Man
Problem
Statement
Method
Manpower
Environment
Cause and Effect (Fishbone Diagrams)
A cause and effect (fishbone) diagram:
●
Breaks problems down into bite-size pieces.
●
Displays many possible causes in a graphic manner.
●
Is also called a cause & effect, 4-M or Ishikawa diagram.
●
Shows how various causes interact.
●
Follows brainstorming rules when generating ideas.
A fishbone session is divided into three parts: Brainstorming, prioritizing, and development of an action plan. Identify the problem statement and brainstorm
the categories in a fishbone diagram. To prioritize problem causes, polling is often used. The three most probable causes may be circled for the
development of an action plan.
Generally, the 4-M (manpower, material, method, machine) version of the fishbone diagram will suffice. Occasionally, the expanded version must be used.
In a laboratory environment, measurement is a key issue. When discussing the brown grass in the lawn, environment is important. A 5-M and E Schematic
is shown in the above illustration.
Material
Machine
Man
Insufficient Training
Variation in Tolerance
Wear and Tear
Keypunch errors
1. Plating
Over Issue updates not made
2. Material thickness
1. Worn numbers on scale keys
3. Scrap & Foreign Elements
2. Containers broken
Pulled wrong parts from location
4. Lengths
Reduce incoming
receipt errors from 4%
to 1% of transactions
Wrong part numbers from dept
Scale #2 more accurate
Suspect pan tare weights
Vendor counts accepted
than scale #1
Scale Calibration
Pulled wrong parts from location
Non-standard sampling procedure
Three different scales
Pulled wrong parts from location
(inadequate sample quantity)
Tare weights not on pans
Interruptions
Measurement
Environment
Method

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IS-IS NOT MATRIX
Problem:
Is
Is Not
Distinctions
What occurs, what objects
are affected?
Where does the problem
occur?
When does the problem
occur?
Extent of problems
Who is involved?

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Document Outline

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