Corrective Action Problem Solving - CJ Kurtz

CJ Kurtz & Associates LLC 1


Corrective ActionProblem Solving

Carol KurtzCJ Kurtz & Associates LLC



Trainer: Carol Kurtz

American Society for Quality (ASQ)Certified Quality EngineerCertified Quality AuditorCertified Quality ManagerCertified Mechanical Inspector

20+ years of Quality & ManufacturingExperience



Course Objectives

Understand 8D Corrective Action &Problem Process

Identify and Use Tools for Each 8DProcess Step

Understand Vocabulary & PrinciplesCompare to Other Fact Based Problem

Solving Methods



Corrective Action

Action to eliminate the cause of adetected nonconformity.

Action to protect the customer fromreceiving or using nonconformingproduct.

Corrective action is taken to preventrecurrence.



Problem Solving

Problem Solving: Typically involves amethodology of clarifying the descriptionof the problem, analyzing causes,identifying alternatives, assessing eachalternative, choosing one, implementingit, and evaluating whether the problemwas solved or not.

8D, PDCA, DMAIC (du-may-ic)



Corrective Action Origins

The origins of the 8-Dsystem actually goes backmany years.

The US Government first‘standardized’ the system inMil-Std-1520 “CorrectiveAction and DispositionSystem for NonconformingMaterial”

Mil-Std-1520 - Firstreleased: 1974

Last Revision was C of 1986 Cancelled in 1995



What is 8D?

8D means Eight DisciplinesIt is a methodology used for solving

problems8D also refers to the form that is used to

document the problem and resolutionAlso called 8-D ReportCorrective Action ReportEW8D Report – East-West-8D



Why 8D?

8D is a structured approach to solvingproblems

Fact BasedData Collection & Analysis

Tests progress and results Verify & Validate

DocumentedHistory – An information database Anticipate future problems Prevent recurrence



8D Corrective Action



Six Sigma DMAIC



Plan Do Check Act - PDCA



Some Vocabulary

ProblemSymptomConcernRoot Problem Failure Mode

EffectCauseSpecial CauseCommon CauseRoot Cause



Verification & Validation

Verification and Validation are often notwell understood. Verification andValidation work together as a sort of‘before’ (Verification) and ‘after’(Validation) proof.Verification provides ‘insurance’ at a point intime that the action will do what it is intendedto do without causing another problem.Predictive.Validation provides measurable ‘evidence’over time that the action worked properly.



Verification & Validation

Step Process PurposeD3 Verification

That the containment action will stop the symptom fromreaching the customer.

ValidationThat the containment action has satisfactorily stoppedthe symptom from reaching the customer according tothe same indicator that made it apparent.

D4 Verification That the real Root Cause is identified.

D5 Verification That the corrective action will eliminate the problem.

D6 ValidationThat the corrective action has eliminated the problemaccording to the same indicator that made it apparent.



Structure of a Problem

Determining the structure of a problemassists in the selection of the correcttools to use.

It may give clues to the nature of the rootcauses.



Structure of a Problem



Structure of a Problem (continued)

TimeExpectedPerformance

Start-up, gap between expected and actual performance:

ActualPerformance

TimeEstablishedPerformance

Recurring change, comes and goes with unknown causes:



Structure of a Problem (continued)

Sometimes we experience positive changesthat need to be investigated so that processesand products may be improved.



Classifying Problems

Correctly categorizing and classifying aproblem precedes any problem solvingeffort.

Ensures proper methods and tools areselected.

If not done, wasted time and effort mayoccur and wrong solutions may beimplemented.



Classifying Problems – Type I

Plant Floor ProblemsRapid response is neededUsually have discernable root causesUsually require less data collection and analysisUsually can be solved by local expertsUsually gradual or sudden problem structures Special causes Specific problem requiring Problem Analysis 8D methodology applies



Classifying Problems – Type II

Technical Problems Permanent corrective actions are neededUsually have difficult to discern root causesUsually require more data collection and analysisUsually require some technical expertise to solveMay be any problem structure Special Causes Specific problem requiring Problem Analysis 8D methodology applies



Classifying Problems – Type III

Process Improvement Major systemic fixes needed Multiple causes and effects May require data collection and analysis May need “systems thinking” to solve Usually requires process owner’s involvement Common cause problem Structures include startup and positive. Others may apply. Broad problems requiring a Situation Analysis Quality Improvement Projects, Continual Improvement

Projects or other methodologies apply.



Problem Solving Tools

Trend Chart Control Chart Pareto Chart Brainstorm Checksheet Histogram Nominal Group

Technique Five Why’s Computer Aided

Engineering APQP

Situation Analysis Flowchart Failure Analysis Database Decision Analysis Action Plan Root Cause Analysis Cause & Effect Diagram Scatter Diagram Design of Experiments Poka Yoke Preventive Action Matrix

There are many, many analysis tools.

You will find that the many other analysis tools, and solution tools, will be important,,however the applicability of any one tool will depend upon the specific problembeing analyzed as well as the available expertise. For example, not all companieshave an employee who is versed in Design of Experiments or FMEA’s.

Unfortunately, it is well beyond the scope of this course to attempt to train all ofthese methodologies.



Problem Solving Tools

Tool Purpose 8D Step

Trend ChartIndicator to track magnitude ofsymptoms

D1 D2 D3 D4 D5 D6D7 D8

Pareto ChartQuantifier to prioritize andsubdivide the problems D2 D8

Paynter Chart Indicator to monitor andvalidate the problems

D2 D3 D6 D8

Repeated WhyMethod to move from symptomto problem description D2

Information DatabaseProcess to find root causeusing Is/Is Not, Differences,Changes

D2 D4 D5 D6

Decision MakingMethod to choose best actionfrom among alternatives D3 D5

Action Plan Record of assignments,responsibilities and timing

D1 D2 D3 D4 D5 D6D7 D8

EW8DReport of problem solvingprocess for managementreview

D1 D2 D3 D4 D5 D6D7 D8



Problem Solving Tools Quiz

ParetoAnalysis

RAC-Root Cause

Analysis

Trend Charts

ProblemSolving

Tools

?

?

ParetoAnalysis

RAC-Root Cause

Analysis

?



D0: Recognize the Symptoms

Detect the problem!Nonconforming ProductOut of Control Conditions on ChartsReworkTrend ChartsWhat others?

D0: Recognize the Symptoms Tools

Trend Chart

Control ChartCustomer Incidents

Warranty Reports

PPM ReportsDFMEA

PFMEA

Pilot BuildsProduct Test Plans




Customer

Receiving /Inventory

Supplier

In-Process Inventory /Shipping

InTransi

t

InTransi

t

Company

Here?

Or Here?

Or Here?

Or Here?

Or Here?Or Here?

Or Here?Or Here?

There are many places where a problem can be identified.



D0: Recognize the SymptomsTrend Chart

A line graph plotting data over time.Use to observe behavior over timeProvides a baseline and visual examination of

trendsNo statistical analysis Look for trends and patternsAsk “Why?”Good for operations/processes where data for

control charts is not available



D0: Recognize the SymptomsTrend Chart

Average Hours Worked Per Employee (3rd shift)4544434241403938373635

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecChange shift starting timesNew entrance opened.Task group established.




Nonconforming ProductOut of Control Conditions on ChartsReworkTrend Charts What others?



D0: Recognize the SymptomsControl Chart

A line graph of a quality characteristicthat has been measured over timeBased on sample averages or individual

samplesIncludes statistically determined Control

Limits.Requires certain assumptions and

interpretation



Interpreting Control Charts

Control Charts provide information as to whether a process is being influenced byChance causes or Special causes. A process is said to be in Statistical Controlwhen all Special causes of variation have been removed and only Commoncauses remain. This is evidenced on a Control Chart by the absence of pointsbeyond the Control Limits and by the absence of Non-Random Patterns or Trendswithin the Control Limits. A process in Statistical Control indicates that production isrepresentative of the best the process can achieve with the materials, tools andequipment provided. Further process improvement can only be made by reducingvariation due to Common causes, which generally means management taking actionto improve the system.

A. Most points are near the center line.B. A few points are near the control limit.C. No points (or only a ‘rare’ point) are beyond the Control Limits.

Upper Control Limit

Lower Control Limit

Average



Interpreting Control ChartsWhen Special causes of variation are affecting a process and making it unstableand unreliable, the process is said to be Out Of Control. Special causes of variationcan be identified and eliminated thus improving the capability of the process andquality of the product. Generally, Special causes can be eliminated by action fromsomeone directly connected with the process.

The following are some of the more common Out of Control patterns:

Upper Control Limit

Lower Control Limit

Average

Tool Wear?

Change ToMachine Made

Tool Broke




Upper Control Limit

Lower Control Limit

Average

Trends

Points Outside of Limits

A run of 7 intervals up or down is a sign of an out of control trend.



Interpreting Control ChartsRun of 7 ABOVE the Line

Run of 7 BELOW the line

A Run of 7 successive points above or below the center line is an out of control condition.



Interpreting Control ChartsSystematic Variables

Cycles

Predictable, Repeatable Patterns




Instability

Freaks

Sudden, Unpredictable

Large Fluctuations, Erratic Up and Down Movements




Mixtures

Typically Indicates a Change in the System or Process

Sudden Shift in Level

Unusual Number of Points Near Control Limits (Different Machines?)




Stratification

Constant, Small Fluctuations Near the Center of the Chart



Control Chart Analysis Reaction

There is a wide range of non-random patterns that require action. Whenthe presence of a special cause is suspected, the following actions shouldbe taken (subject to local instructions).

1. CHECKCheck that all calculations and plots have been accurately completed,including those for control limits and means. When using variable charts,check that the pair (x bar, and R bar) are consistent. When satisfied thatthe data is accurate, act immediately.




2. INVESTIGATEInvestigate the process operation to determine the cause.Use tools such as:

BrainstormingCause and EffectPareto Analysis

Your investigation should cover issues such as:The method and tools for measurementThe staff involved (to identify any training needsTime series, such as staff changes on particular days of the weekChanges in materialMachine wear and maintenanceMixed samples from different people or machinesIncorrect data, mistakenly or otherwiseChanges in the environment (humidity etc.)




3.ACTDecide on appropriate action and implement it.Identify on the control chart

The cause of the problemThe action taken

As far as possible,eliminate the possibility of the special cause happeningagain.



4. CONTINUE MONITORINGPlotting should continue against the existing limitsThe effects of the process intervention should become visible. If not, it shouldbe investigated.Where control chart analysis highlights an improvement in performance, theeffect should be researched in order that:

Its operation can become integral to the processIts application can be applied to other processes where appropriate

Control limits should be recalculated when out of control periods for whichspecial causes have been found have been eliminated from the process.

The control limits are recalculated excluding the data plotted for the out ofcontrol period. A suitable sample size is also necessary.

On completion of the recalculation, you will need to check that all plots liewithin the new limits




D0: Recognize the SymptomsOther Indicators

Customer Concerns & IssuesWarranty DataQuality ReportsProduct Quality Planning



D1: Establish the Team

Establish a small group of people withthe knowledge, time, authority and skillto solve the problem and implementcorrective actions. The group selects ateam leader.

D1: Establish the Team Tools

Brainstorm



D1: Establish the TeamThe 8D Team Members

Cross Functional or Multi-DisciplinaryProcess OwnerTechnical ExpertOthers involved in the containment,

analysis, correction and prevention of theproblem



D1: Establish the TeamTeam Roles

Several roles need to be established for the team. These roles are:Leader, Champion, Record Keeper (Recorder), Participants and (ifneeded) Facilitator.

LeaderGroup member who ensures the group performs its duties andresponsibilities. Spokesperson, calls meetings, establishes meetingtime/duration and sets/directs agenda. Day-to-day authority, responsible foroverall coordination and assists the team in setting goals and objectives.

Record KeeperWrites and publishes minutes.

ParticipantsRespect each others ideas.

Keep an open mind.

Be receptive to consensus decisionmaking.

Understand assignments and acceptthem willingly.

ChampionGuide, direct, motivate, train,coach, advocate to uppermanagement.



D1: Establish the TeamProblem Solver Characteristics

Persistent Intuitive (supported by mechanical aptitude) Logic & disciplineCommon senseAbility to balance prioritiesOwnership Inquisitive and willingCreative and open mindedNeeds proof & facts



D1: Establish the TeamEffective Team Characteristics

LeadershipClearly define goalsClearly defined responsibilitiesTrust & RespectAuthorityPositive AtmosphereGood two way communicationEffective action plan with timing



D1: Establish the TeamManagement Responsibility

Provide time and resoucesProvide mentoringUnderstand need for changeRecognize accomplishments & team

process



D1: Establish the TeamBrainstorming

Generate a great number of possiblesolutions to a problem

Use to avoid conventional or in-the-boxthinking

Overcome mental blocks, inspirecreativity

Take advantage of team synergyIdeas from different perspectives

Brainstorming is a method for developing creative solutions to problems. It works byfocusing on a problem, and then deliberately coming up with as many deliberatelyunusual solutions as possible and by pushing the ideas as far as possible.

One approach to brainstorming is to 'seed' the session with a word pulled randomlyfrom a dictionary. This word as a starting point in the process of generating ideas.During the brainstorming session there is no criticism of ideas - the idea is to openup as many possibilities as possible, and break down preconceptions about thelimits of the problem.

Once this has been done the results of the brainstorming session can be analyzedand the best solutions can be explored either using further brainstorming or moreconventional solutions.



D1: Establish the TeamTeam Check List

Team Check List Yes No

Has a champion accepted responsibility for monitoring the measurables?

Have measurables been developed to the extent possible?

Have special gaps been identified? Has the common cause versusspecial cause relationship been identified?

Has the team leader been identified?

Does the team leader represent the necessary cross-functionalexpertise?

Has team information been communicated internally and externally?

Has the team agreed upon the goals, objectives, and process for thisproblem solving effort?

Is a facilitator needed to help keep process on track and gain consensus?

Does the team have regular meetings?

Does the team keep minutes and assignments in an action plan?

Does the team work well together in following the process andobjectives?



D2: Problem Description

Describe the problem in measurableterms. Specify the internal or externalcustomer problem by describing it inspecific terms.

D2: Problem Description Tools

Problem Statement

Five Why’sObservation at gemba

Flowcharts

Situation AnalysisPareto Chart

Paynter Chart

Describe Problem

Information Database

ChecksheetHistogram

Control Charts



D2: Problem DescriptionProblem Statement

Problem statement =Object + concern + quantificationExample:

20% of Tuesday’s first shift production ofend cap #3245A have a ¼” to ¾” crack atthe lower left corner of the strain relief hole.

Remember: A well defined problem ishalf solved!



D2: Problem DescriptionFive Why’s

A technique for stepping through successive layers ofsymptoms to find the root problem statement.

Go to the point of occurrence of the problem (gemba) Begin asking “Why?” Using a flowchart, track back from symptom to

symptom until you find: The root cause A level where permanent corrective action can be

implemented A point where “Why?” can no longer be answered



D2: Problem DescriptionFlowchart

A picture of aprocess usingsymbols and arrowsto representsequence of thesteps.



D2: Problem DescriptionSituation Analysis

Tool used to break broad problems intosmaller prioritized pieces to attack one ata time.

Many problem solving efforts start withlarge, messy, poorly defined, unforcusedissues.

This method is detailed in the book TheNew Rational Manager by Kepner &Tregoe



D2: Problem DescriptionPareto Analysis

A Pareto chart offers the following benefits:Focuses on the problems or causes of

problems that have the greatest impactDisplays the relative significance of

problems or problem causes in a simple,quick-to-interpret, visual format

Can be used repeatedly to producecontinuous improvements

To construct a Pareto chart, the following steps are recommended:

1) Choose a problem that needs to be addressed.2) Identify the causes of the problem based on existing data and through

brainstorming.

3) Decide on how these problem causes will be monitored for the data collection forthe Pareto chart, e.g., frequency of occurrence?, cost?, etc.

4) Define the duration and time frame of the data collection - it should be longenough to provide meaningful information about the real situation.

5) Conduct the data gathering according to the defined time frame, e.g., monitorthe frequency of occurrence or cost impact of each problem cause encountered,ensuring that causes not identified earlier for monitoring must still be counted ina catch-all bin ('Others' category).

6) Tabulate the problem causes in order of decreasing frequency, and assign acolumn each for:

a) the frequency of occurrence (or cost impact);b) the percentage share of the cause; and

c) the cumulative percentage corresponding to each problem cause.

7) Construct the Pareto chart using the tabulated data and following the Paretochart format discussed earlier.

8) Interpret the Pareto chart and select the 'vital few' that need to be addressedimmediately.



D2: Problem DescriptionPareto Analysis

-100%50Total

100%4%2Others

96%2%1Resin Bleed-out

94%2%1Cratering

92%2%1Bond Pad Peel-off

90%2%1Corrosion

88%4%2Silicon Dust on

Bond Pad

84%6%3Excessive Probe

Damage

78%18%9Foreign Contam

on BondPad

60%22%11Unetched Glass

on BondPad

38%38%19Bonder Set-up

Issues

Cum Percent(%)

Percent(%)Frequency

Ball LiftingCause



D2: Problem DescriptionPaynter Chart

This chart is combination of Trend andPareto charts.

Provides information on actions takenand shows effects.

Can be modified for Returns, Scrap,Rework, etc.



D2: Problem DescriptionPaynter Chart

Number of 3rd shift workers affectedProblems: July Aug Sept Oct Nov Dec TotalTraffic jam on Hiway 90 84 4 3 0 90Buses Late 30 30 9 8 30 30Not Enough Parking 17 16 17 8 0 17Bad Weather 9 10 20 21 9 9Road Construction 4 0 0 0 21 4

150 140 50 40 60 150

= Containment Action: Change Shift Starting Time

= Corrective Action: Open second gate,change shift starting times back to 'normal'.

= Corrective Action: Task Group established.

% Late Employees Third Shift # Late Employees100 60

90 54

80 48

70 42

60 36

50 30

40 24

30 18

20 12

10 6

0 01 2 3

Buses Late Bad Weather Not Enough Parking

Average Hours Worked Per Employee (3rd shift)4544434241403938373635

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecChange shift starting timesNew entrance opened.Task group established.

Paynter Chart template is available online at http://www.cjkurtz.com/qualitytools.htm



D2: Problem DescriptionInformation Database

A tool for organizing all data about aproblem into four categories: What,Where, When, Extent.

Used for Problem AnalysisDetailed in The New Rational Manager

by Kepner/Tregoe



D2: Problem DescriptionInformation Database

Is Is Not

What: What is the object you are having a problem with? What could be happening but is not?

What is the problem concern? What could be the problem concern, but is not?

Where:Where do you see the concern on the object? Be specificin terms of inside to outside, end to end, etc.

Where on the object is the problem NOT seen? Does theproblem cover the entire object?

Where (geographically) can you take me to show me theproblem? Where did you first see it?

Where else could you have observed the defective object,but did not?

When:When in time did you first notice the problem? Be asspecific as you can about the day and time.

When in time could it have first been observed, buy wasnot?

At what step in the process, life or operating cycle do youfirst see the problem?

Where else in the process, life or operating cycle mightyou have observed the problem, but did not?

Since you first saw it, what have you seen? Be specificabout minutes, hours, days, months. Can you plot trends?

What other times could you have observed it but did not?

How Big: How much of each object has the defect? How many objects could be defective, but aren't?

What is the trend? Has it leveled off? Has it gone away? Isit getting worse?

What other trends could have been observed, but werenot?

How many objects have the defect? How many objects could have had the defect, but didn't?

How many defects do you see on each object? How many defects per object could be there, but are not?

How big is the defect in terms of people, time, $ and/orother resources?

How big could the defect be, but is not?

What percent is the defect in relation to the problem?



D2: Problem DescriptionChecksheet

Checksheets are simple and effectivemethod of gathering informationon the job.

Ensures consistency of data collected.Simplifies data collection and analysis.Highlights trends.Spots problems.



D2: Problem DescriptionChecksheet

5451831Totals

12048Missing screws

1001Missing holes

4151422Nicks

Totals3rd Shift2nd Shift1st ShiftDefect

Date 12-16-04

Part Defect ChecksheetPart Number 621532-B



D2: Problem DescriptionHistogram

Chart using bars of varying height toshow frequency distribution of somecharacteristic.

Use for problem recognition, problemdefinition, data analysis, and valifdationof corrective actions.

Visually evaluate spread, centering,capability.



D2: Problem DescriptionHistogram

23mm OD HistogramP/N 543612 on Machine 6

0

1

2

3

4

5

6

19 21 23 25 27M

ore

Outside Diameter

Freq

uen

cy

Frequency



D3: Containment

Define and implement those intermediateactions that will protect the customerfrom the problem until permanentcorrective action is implemented.

Verify with data the effectiveness ofthese actions.

D3: Containment Tools

Contain Symptoms

QuarantineSort

Inspect

FlowchartDecision Analysis

Action Plan

Problem Prevention

Verify Containment

Pilot TestPaynter Chart



D3: ContainmentContain Symptom Flow

Stop Defect at EachPoint in the ProcessBack to the Source

Validate that ActionTaken is Fully Effective

Immediate Containmentwith Current

Information andProblem Description

Choose

Verify Before

Implement

Validate After Implementation

Certify parts and ConfirmCustomer DissatisfactionNo Longer Exists

DetermineEscape Point

Should an existing ‘check’ (control)have caught the defect?



D3: ContainmentObjectives

The objective of this step is to isolate the effects of the problemby implementing containment actions.

Once a problem has been described, immediate actions are to betaken to isolate the problem from the customer. In many casesthe customer must be notified of the problem.

These actions are typically ‘Band-aid’ fixes. Common containment actions include:

100% sorting of components

Items inspected before shipment Parts purchased from a supplier rather than manufactured in-

house Tooling changed more frequently Single source



D3: ContainmentContainment Action Checksheet

Have you coordinated the action plan with the customer?

Have you ensured that implementation of the containment action will not create otherproblems?

Are responsibilities clear for all actions?

Has baseline data been collected for comparison?

Is data being collected in a form that will validate the effectiveness of the containmentaction?

Have you validated the containment action?

Have you specially identified the 'certified' parts?

Have you certified that parts no longer have the symptom?

Have you verified that the action taken is FULLY effective?

Has the concern been stopped at each point in the process back to the source?

Has immediate containment action been taken to protect the customer?

NoYesContainment Action Checksheet



D4: Determine Root Causes

Identify potential causes which couldexplain why the problem occurred.

Test each potential cause against theproblem description and data.

Identify alternative corrective actions toeliminate root cause.

D4: Determine Root Causes Tools

Find Root Cause

Five Why’sObservation at gemba

Root Cause Analysis

Cause & Effect DiagramScatter Diagram

Failure Analysis

PoCAE

DOE

SIM

VerifyConduct with / without study to verify root cause



D4: Determine Root Causes

Root Cause of Event (Occur or Occurrence)What system allowed for the event to occur?

Root Cause of EscapeWhat system allowed for the event to escape

without detection?



D4: Determine Root CausesRoot Cause Analysis

Process of analyzing “is” & “is not” pairsof information for differences andchanges that lead to root cause



D4: Determine Root CausesRoot Cause Analysis

Enhanced Problem Description -->

Increasing --> SPECIAL CAUSE!What is the trend?

Once per dayHow many defects per object?

Third shift (4:00PM)How many objects have the defect?

How Big:

AfternoonWhen seen in process (life cycle)

Ever sinceWhen else seen

July 7, 1996First seen

When:

East bound I-70 near Main StreetSeen geographically

I-70 ExpresswaySeen on object

Where:

Late EmployeesDefect

Heavy trafficObject

What:

Is NotIs



D4: Determine Root CausesCause & Effect Diagram Shows the relationship of causes and sub-causes to

an identified effect or problem. Clearly identify theproblem or effect to be diagrammed in the box at theright

Draw the fishbone structure Identify the major categories, factors, the causes

related to the effect. Brainstorm, or note the causes of the problem that fall

within each of the major categories. Each branch may have sub-branches, or sub-sub-

branches As ideas are generated determine which branch of the

"bone" they should be placed



D4: Determine Root CausesCause & Effect Diagram



D4: Determine Root CausesScatter Diagram Scatter diagrams are used to study possible

relationships between two variables. Although thesediagrams cannot prove that one variable causes theother, they do indicate the existence of a relationship,as well as the strength of that relationship.

A scatter diagram is composed of a horizontal axiscontaining the measured values of one variable and avertical axis representing the measurements of theother variable.

The purpose of the scatter diagram is to display whathappens to one variables when another variable ischanged. The diagram is used to test a theory that thetwo variables are related. The type of relationship thatexits is indicated by the slope of the diagram.



D4: Determine Root CausesScatter Diagram

Strongly correlated




Moderately correlated




No Correlation



D4: Determine Root CausesDesign of Experiments - DOE

Shanin’s Red X Component SearchTaguchi’s MethodsClassical Design of Experiments



D5: Select & Verify CA

After root causes and possible correctiveactions have been identified, select thecorrective actions that will permanentlycorrect the problem.

Decision analysis may be needed if thechoice is not obvious.

Verify that the selected corrective actionswill resolve the problem.

D5: Determine & Verify CA Tools

Select Corrective Action

Decision Analysis – Kepner/TregoePoka Yoke

DOE

SIM

Verify Corrective Action

Pilot TestMaterial Characterization

CAE



D5: Select & Verify CAPoka Yoke

Poka Yoke Devices

Are Built within the ProcessIn General Have Low CostHave the Capacity for 100%

Inspection

Remember SQC is performed outside theprocess which adds cost and allows defectsto escape the system.




OrientationPoka Yoke

Interference FitPoka Yoke




Floppy diskshave manypoka-yokes builtin. One exampleis you cannotinsert the diskinto the drivecompletely if thedisk is upsidedown. This isbecause of thecorner notch[#1].

720k disks haveno hole [#2]while HD diskshave hole(mechanismsenses)[#3].

Spring loadedshuttermechanism - Doyou rememberthe old 5.25 inchfloppies from theearly to mid-1980’s? Failsafedisk surfaceprotection [#4].

Slide Tab toprotect againsterasure.Mechanismsenses [#5].

‘Precision’ alignment. Disk alignment holes and notches [#6] ensure the disk isproperly aligned and also provides a ‘focus’ area for manufacturing.

2

1 1

3

4

55

4 6 66




Computer Files

Microsoft: File typeidentified by filename suffix. If onedoes not add thecorrect suffix, theprogram the file isfrom will notrecognize it.

Macintosh PokaYoke (1984): Filetype and creatorapplication areidentified andembedded in the firstpart of every file. Filename plays NO partin recognition by theoriginating program.

Computer FloppyDrives

Microsoft: Disk mustbe inserted and ejectedby hand. It is possibleto eject a disk while it isbeing written to.

Macintosh Poka Yoke(1984): Disk drive grabsdisk as it is beinginserted and draws it inand seats it. Diskcannot be manuallyejected. You must dragthe ‘desktop’ icon forthe disk to the ‘Trash’.The drive then ejectsthe disk as long asthere are no diskoperations taking place.

New lawn mowers arerequired to have asafety bar on thehandle that must bepulled back in order tostart the engine. If youlet go of the safety bar,the mower blade stopsin 3 seconds or less.This is an adaptation ofthe "dead man switch"from railroadlocomotives.

Warning lights alert thedriver of potentialproblems. Thesedevices employ awarning methodinstead of a controlmethod.



D5: Select & Verify CACorrective Action Check List

Corrective Action & Verify Check List Yes No

Has corrective action been established?

Does it meet the required givens?

Have different alternatives been examined as possible corrective actions?

Have Poke-Yoke techniques been considered?

Has each alternative been screened?

Have the risks involved with the corrective action been considered?

Was the corrective action verified?

Was the corrective action proven to eliminate the root cause?



D6: Implement & Validate CA

Implementation can proceed when bestcorrective action has been selected &verified.

An effective implementation planreduces problems.

Validation is obtained by trackingperformance over time afterimplementation to ensure the correctionsare permanent.

D6: Implement & Validate CA Tools

Implement Corrective Action

Action PlanSolution Analysis – Reverse Cause & Effect

Problem Prevention

Validate Corrective Action

Paynter ChartChecksheet

Histogram

Control Chart



D6: Implement & Validate CAImplementation Check List

Implement CA & Validate Over Time Yes NoHas the implementation plan been constructed to reflect ProductDevelopment Process events and engineering change process?

Do the corrective actions make sense in relation to the cycle plan for theproducts?

Have both Design and Process FMEAs been reviewed and revised asrequired?

Have significant / safety / critical characteristics been reviewed and identifiedfor variable data analysis?

Do control plans include a reaction plan?

Is simultaneous engineering used to develop process sheets andimplement manufacturing change?

Is the Paynter Chart in place for validating data?



D7: Prevent System Recurrence

Implement the corrective actions in otherpotentially affected areas.

Ensure the systems that allowed theproblem to occur and escape have beencorrected.

The problem is now Type III requiring alarger scale continual improvementproject of some type.

D7: Prevent System Recurrence Tools

Spread Solution

Preventive Action MatrixTrend Chart

Control Chart

BrainstormPaynter Chart

Five Why’

DFMEAPFMEA

Product Test Plan

Control PlanOperator Instructions

Fix SystemProcess Improvement

Process Re-design

(All other problem solving tools)



D7: Prevent System RecurrencePrevent System Problems Check List

Prevent System Problems Check List Yes NoHave the system prevention practices, procedures & specification standardsthat allowed the problem to occur and escape been identified?

Has a champion for system prevention practices been identified?

Does the team have the cross-functional expertise to implement the solution?

Has a person been identified who is responsible for implementing the systempreventive action?Does the system preventive action address a large scale process in abusiness, manufacturing or engineering system?

Does the system preventive action match root cause (occur & escape) of thesystem failure?

Does the team utilize error proofing and successive checks on a proactiveon-going basis to eliminate the occurrence and escape of all defects?

Has a pieces over time (Paynter Chart) been used to indicate that the systempreventive actions are working?

Has the System Preventive Action been linked to the Product Developmentphase?



D8: Congratulate the Team

Recognize the collective efforts of yourteam. Publicize your achievement. Shareyour knowledge and learning.

D8: Congratulate the Team Tools

Recognize the Team and Look for Next Opportunity

Trend ChartControl Chart

Pareto Chart

BrainstormPaynter Chart

Checksheet



D8: Congratulate the TeamCongratulate The Team Checksheet

Congratulate The Team Checksheet Yes NoHave documented actions and lessons learned been linked to ProductDevelopment Process for future generations of products?

Has appropriate recognition for the team been determined?

Has application for patents & awards been considered?

Has team been reassessed?

Has the team analyzed data for next largest opportunity?

The form of recognition can vary, depending upon the complexity and severity of theproblem. It is important to document what was learned while solving the problem sothat this information can be used by others for planning.

A description of the various actions carried out, together with the analysis andresults obtained through the problem solving process, provide information that canbe used to prepare a case study report. Case study reports include the purpose andobjective, the procedure or problem solving steps followed, the data obtainedthrough various investigative methodologies and the analysis of data in the form ofresults shown by charts and graphs, conclusions and recommendations.

This final step in the problem solving process is to conclude the successful efforts ofthe team is to acknowledge the significance and value, in quantifiable terms, ofsolving the problem for the customer and for improving quality and productivity forthe company.



References

http://elsmar.com/ http://www.isixsigma.com/spotlight/default.asp http://www.isixsigma.com/dictionary/glossary.asp http://www.asq.org/learn-about-quality/ Prince Corp, Corrective Action Manual The New Rational Manager, Kepner & Tregoe http://deming.eng.clemson.edu/pub/tutorials/ http://www.qualityspctools.com/menu.html Ford Team Oriented Problem Solving http://www.cjkurtz.com/qualitytools.htm

Documents

Corrective Action Problem Solving - CJ Kurtz