EasyProblemSolving
Cause & Effect
What is a Cause & Effect Diagram
Also known as fishbone, C&E, Ishikawa diagram
Fishbone shaped diagram with Effect (Y, output) being the head and Bones as the major causes (Xs). This is about cause and effect and not symptoms
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It can have a fair amount of detail in a visual format, which is easy to read and relate to.
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Removes personal biases - a team tool
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Keeps focus on the problem
When to use Cause & Effect Diagram
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To arrive at a root cause
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Focus on causes and not symptoms
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To brainstorm & visually present, the output of a brainstorming session
How to make a Cause & Effect Diagram
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The tool involves brainstorming - so the rules apply
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Place the problem statement on the right side of the board, vertically in the middle
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Now, either ask the team for major cause areas or use
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6 Ms: Man, Machine, Method, Mother Nature, Material & Measurement - remove any that don't apply
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Major process steps
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Use regions (increase sales problem)
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previously collected data to write bones and get consensus
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So now you have the head and major bones
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Let's brainstorm on causes related to each bone
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Drill down further into each sub cause - ask "why", ask "what causes it" "why does this happen" - this may then be placed a sub bone
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This goes on, until either you start going out of your control area or team can't answer any more
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Once completed
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look for causes that appear repeatedly
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you can highlight the prominent ones and get them voted upon to prioritize
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do confirm the frequency of causes, if low, their impact on the problem may also be low
Variations of Cause & Effect Diagram
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CEDAC - Cause and Effect with Addition of Cards
Example of Cause & Effect Diagram
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The head is why low core production hours
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Major bones are based on 6 Ms
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This example only shows till level 2 causes , you can create further bones by adding a vertical / slanting arrow to the sub bone
