Affinity Diagram

A useful tool to help improve the effectiveness of your brainstorming and follow up plans.

Affinity Diagram (island chart)The Affinity Diagram, KJ Method, or Island Chart is named after Kawakita Jiro a Japanese anthropologist.Useful for gathering and arranging opinions, ideas, suggestions, etc.,Organized into sub-groups based on a common relationship or theme.Helps refine brainstorming providing a path for further investigation and action.

Affinity Diagrams Boost the Effectiveness of BrainstormingSeparates the issue into independent causes and allows focused brainstorming on sub- topics.Facilitates more depth & breadth in brainstorming Prioritizes the causes according to group consensusLeads to a more thorough review and logic for actions

Affinity DiagramWrite down ideasLook for natural groupings and arrange similar ideas together Look for trends, themes and overlapPrioritize main topicsPlan Actions that will address the highest priority islands

Basic Steps to making an Affinity DiagramBrainstorm ideas writing each idea on an individual card.Place the cards face up on a table. Read each idea to the group.Arrange the ideas into common themes.Talk about and refine the groupings and look for inter-relationships.Give each island a title.

Write each idea on a card. Lay the cards out on a table.melt tempdiameter of holediameter of the stemdifferences between molds cool timeplastic colortype of plasticmold wearinstallation forcetime delay after moldback pressuresmooth stemdraftmodificationsorder installedinterference fitSPCdropped casterfell out 100% inspectmissed inspectioncaster not missingreduce variationbuild errorintentional flashshort shotshrinkfeeder went emptyProblem: What causes missing casters and what could be done to fix it?

Begin to arrange cards into natural groups.melt tempdiameter of holediameter of the stemdifferences between molds cool timeplastic colortype of plasticmold wearinstallation forcetime delay after moldback pressuresmooth stemdraftmodificationsorder installedinterference fitSPCdropped casterfell out 100% inspectmissed inspectioncaster not missingreduce variationbuild errorintentional flashshort shotshrinkfeeder went emptyProblem: What causes missing casters and what could be done to fix it?

Arrange Ideas into Sub-groups(distinguish between causes and solutions)Put similar ideas togetherBucketSF ProcessOperatorAutomationOtherCastermelt tempdiameter of holediameter too smalldifferences between molds cool timeplastic colortype of plasticmold wearinstallation forcetime delay after moldback pressuresmooth stemdraftmold modificationsorder installedinterference fitSPCdropped casterfell out 100% inspectmissed inspectioncaster not missingreduce variationbuild errorintentional flashshort shotSPCintentional flashshrinkfeeder went empty

Differences in in DiameterWhat causes missing casters?

After the ideas are arrangedLook over the groupings for additional thoughts or insight about the problem.Write down any new ideas that come up and place them accordingly. Rank the ideas using nominal group technique to prioritize further work.That gives me another great idea!

Rank The Ideas(Nominal Group Technique)Focus most of our attention investigating things that could cause a difference in diameter.

Sheet1

LetterCauseEllenSteveJeffJulieDaveTerryTotalCountRankTop 3

APlastic Color0020

BHole Diameter5545322461*

CBuild error0011

DMold modifications1119

EMold wear1221645

FShrink1118

GDraft0023

HType of plastic2217

ITime Delay after mold135934

JOrder installed0021

KDropped caster0012

LInstallation force0022

MFeeder went empty0013

NSmooth stem32526

OStem Diameter too small4354432362*

PMelt temp0016

QCool time11110

RBack pressure0017

SShort shot0018

TMissed inspection0019

UCaster not missing0015

VFell out0014

WDifferences between molds243541853*

100% Inspection

Intentional Flash

SPC

Reduce variation

interference fit

Sheet2

Sheet3

Plan Further WorkRefine ideasDevelop investigation planGather data.Brainstorm for solutionsDevelop solutions that solve the broad categories.Be sure you have significant actions to address the highest priority areas.

What could we do to the design so that any differences in diameter wont be an issue?

Things to remember in using an Affinity diagramRapidly group ideas that seem to belong together. Copy an idea into in more than one group if appropriate. Look at small groups. Should they belong in a larger group? Do large groups need to be broken down more? Wait until most of the ideas have been sorted to decide on titles.

Thank you!