7-improving unstable processes

8/8/2019 7-Improving Unstable Processes

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7-1

Investigate & FixSpecial Causes

TheQualityImprovementModel

Use SPC toMaintainCurrentProcess

Collect &Interpret

Data

SelectMeasures

DefineProcess

Is

ProcessCapable

?

ImproveProcessCapability

IsProcessStable

?

Investigate &Fix Special

Causes

No

Yes

No

Yes

Investigate & Fix Special Causes

Purpose:Assure stability of the

measures.

Establish permanency ofsolutions to recurring specialcauses.

Improve procedures andtraining.


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Unstable Process

Time

Quality Characteristic

Control Chart

UCL

CL

LCL

How dowe improve an unstable process?


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Potential Special Causes

Lack of standardization

Lack of consistent process conditions

Uncontrolled process variables

Unknown process variables

Fluctuating business environment

Equipment malfunctions

Unstable measurement process

Changes in process inputs


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The Improvement Process

Study the Symptoms

Theorize Causes Establish True

Causes

Propose AlternativeSolutions

Select & ApplySolution

MaintainImprovements

We must take the time to identify the causebefore attempting to solve the problem.

Diagnose Solve


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Special Cause Action Plan

(S.C.A.P.)

A planned sequence of activities for investigating andtaking action on a problem which has been detected.

Provides a prioritized listing of potential special causes.

The S.C.A.P. should be updated whenever necessary.

Actions1) Investigation

2) Compensation3) Documentation

4) Correction

5) Prevention

Note: This is the most important part in implementing S.P.C.


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Investigative Action

Systematic detective work to determine the rootsource of the special cause. The investigativeactions should be directed toward determining:

What When Why Where

Unless the urgency of special cause dictates otheraction, investigative action should precede any otheractions. Regardless of the urgency, investigative actionshould always be taken at some point.

Note: This is the most important part of the S.C.A.P..


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Investigate & FixSpecial CausesCompensating Action

Adjustment made to the process after a nonconformity,

defect, or other undesirable process situation in an attemptto restore the process to the desired state, withoutaddressing the underlying cause of the situation. (ISOdefinition)

Taking action on the process in the form of adjustments to theprocess. These actions do not remove the cause but are knownto adjust the process in a favorable direction. (Adjusting)

OR

T

aking action on the process to remove the symptom of thespecial cause. This may not prevent the same problem fromrecurring in the future. (Fixing)

Adjustments may help one part of the process but could bedetrimental to others.


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Documentation

Recording the suspected cause of the problem, whatactions were taken and how effective the action was.

Benefits:


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Cause

D

Cause

G

Cause

A

Cause

B

Cause N All

others

Frequency

ofOccurrence

Pareto of Causes

Note: Putting resources to eliminating Cause D will result in most significantImpact on process improvement.


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Corrective Action

Actions taken to eliminate the causes of existingnonconformity, defect, or other undesirable situation inorder to prevent recurrence (ISO definition).

Permanent removal of the root source of recurringspecial causes that have been identified.

Focus is on preventing major recurring special causes.

Implementation results in variability reduction.


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Preventive Action

Action taken to eliminate the causes of a potentialnonconformity, defect, or other undesirable situationin order to prevent occurrence.(ISO definition)

Permanent removal of the root source of apotential special cause that could affect theprocess.

May involve using learning's from one process onanother process where the special cause might alsooccur.


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A standard way to perform a task.

A standard range that a key process variable should

be within.

Standards should be audited.

Control To A Standard

Note: S.O.P.'sNOT being followed can be a major reason for instabilities oncontrol charts!


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Control "Charts" will NOT improve the process!

S.C.A.P's IMPROVE the process

Provide a procedure for operations to follow in

identifying and removing the special cause symptom.

Promote a standardized approach to investigatingand compensating for special causes.

Provide a vehicle for documenting causes found and

actions taken to aid in future problem solving.

Why S.C.A.P.'s?


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7-14


Rating of

Importance to

Customer

10 1 9 9 5 8

1 2 3 4 5 7

Bea%

MeltTe

p

BottleOutput

Clait

Weight

Wall

Vaiation

Total

Process Step Process Input

Melt Resin Resin 9 9 3 9 9 9 324

Blow Bottle Mold Design 9 0 9 9 0 9 324

Ext ude Pa i on P og a ing 3 3 9 0 9 9 231Ext ude Pa i on Die Tip Te p 3 3 3 9 3 9 228

Blow BottleMold Water

Temp9 0 9 3 0 0 198

Blow Bottle

Water

Volume/Cooli

n Rate

9 0 9 3 0 0 198

Ext ude Pa i on Head De ign 3 9 3 3 3 9 180

Ext ude Pa i on Tooling 3 3 3 3 3 9 174

Blow Bottle Pinch Design 9 0 9 0 0 0 171

Melt Re in Ba ell Te p 3 9 9 1 3 3 168

Melt Re in S ew Speed 3 9 9 1 3 3 168

Melt Re in S ew De ign 3 9 9 1 1 1 142

Blow Bottle

# of Mold

Cooling

Zones

9 0 3 0 0 0 117

Tail Detab

Time from

extraction to

Detab

9 0 3 0 0 0 117

Re e be The C&E Mat ix

Note: C&E is a good place to start building control strategies. This information

will be used to develop a Failure Modes Effect Analysis (FMEA)


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Failure Modes and Effects AnalysisFailure Modes and Effects Analysis

A Tool forDeveloping SCAP's


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A structured approach to:A structured approach to:

Assist in developing SCAP's

identifying the ways in which a product or processcan fail

estimating the risk associated with specific causes

prioritizing the actions that should be taken toreduce the risk

evaluating the design validation plan (product) orthe current control plan (process)

Primary DirectivePrimary Directive:: Identify ways the product orprocess can fail and eliminate or reduce the risk offailure

FMEA Definition


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Vague

Workmanship

S andards

Poor Con rolPlans & SOPs

Raw Ma erial

Varia ion

Poorly DevelopedSpeci ica ion

Limi sMeasuremen

Varia ion (Online

and QC)

Machine

Reliabili y

Po en ial

Sa e yHazardsUnclear Cus omer

Expec a ions

D. H. Stamatis, FMEA:FMEA from Theoryto Practice, Quality Press, 1995

Poor Process

Capabili y

Cumula ive RiskCumula ive Risk

Where Do Risks Come From?


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Key tool of process team to improve the process in apreemptivepreemptive manner (before failures occur)

Used toprioritizeprioritize resources to insure process

improvement efforts are beneficial to customer

Used to documentdocumentcompletion of projects

Should be a dynamicdynamicdocument, continually reviewed,amended, updated

Role of FMEA


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AnalyzesAnalyzes new processes

IdentifiesIdentifies deficiencies in the process control plan

EstablishesEstablishes the priority of actions

EvaluatesEvaluates the risk of process changes

IdentifiesIdentifies potential variables to consider in E ploratoryData Analyses (EDA) and Design of E periments(DOE) studies

GuidesGuides the development of new processes

HelpsHelps set the stage for breakthrough

Purposes of FMEA


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Investigate & FixSpecial CausesFMEA Inputs and Outputs

InputsInputs Process map

C&E matri

Process history

Process technical procedures

OutputsOutputs

List of actions to prevent causes or to detect

failure modes History of actions taken


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Investigate & FixSpecial CausesFMEA Team

Team approach is necessary

Recommended representatives:

Design

Practitioners / Operators / Supervisors Quality

Reliability

Maintenance

Materials

Testing

Supplier


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Failure Mode

Effect

Cause

Current Controls

Severity, Occurrence, Detection

Risk Priority Number (RPN)

FMEA Terms

Next, Going to define each of these terms


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Investigate & FixSpecial CausesFMEA E ercise

InpuFailure

ModeE ec s Causes Con rols

As we go through the different definitions and terms,complete the form below for your process


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7-24

Investigate & FixSpecial CausesFailure Mode - Definition

Failure ModeFailure Mode - the way in which a specific process input fails -

if not detected and either corrected or removed, will cause theeffect to occur

Can be associated with a defect (in discrete manufacturing) or aprocess input variable that goes outside of specification

o Anything that an operator can see thats wrong isconsidered a failure mode

E amplesE amples

o Incorrect PO number

o Sample Size too small

o Dropped call (customer service)o Temperature too high

o Surface contamination

o Paint too thin


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Investigate & FixSpecial CausesEffect - Definition

EffectEffect - impact on customer requirements

Generally e ternal customer focus, but can also includedownstream processes

E amplesE amples

Incorrect PO number: Accounts receivable traceability

errors Dropped call: Customer dissatisfaction

Temperature too high: Paint cracks

Surface contamination: Poor adhesion

Paint too thin: Poor coverage


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Investigate & FixSpecial CausesCause - Definition

CauseCause

Sources of process variation that causes the failure mode tooccur

Identification of causes should start with failure modesassociated with the highest severity ratings

E amplesE amples Incorrect PO number: Typographical error

Dropped call: Insufficient number of CS representatives

Temperature too high: Thermocouple out of calibration

Surface contamination: Overhead hoist systems Paint too thin: High solvent content


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Investigate & FixSpecial CausesCurrent Controls - Definition

Current ControlsCurrent Controls

Systematized methods/devices in place to prevent ordetect failure modes orcauses (before causingeffects)

Prevention consists of mistake proofing, automatedcontrol and set-up verifications

Controls consist of audits, checklists, inspection,laboratory testing, training, SOPs, preventivemaintenance, etc.


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Failure Mode 1

Failure Mode 2E ec 1

Note that the relationship between the failure mode and the effect is not

always 1-to-1

E ec 1

E ec 2

Failure Mode 1

Linking Failure Modes to Effects


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7-29

Investigate & FixSpecial CausesRisk Priority Number (RPN)

The output of an FMEA is the Risk Priority Number

The RPN is a calculated number based oninformation you provide regarding

o the potential failure modes,

o the effects, and

o the current ability of the process to detect thefailures before reaching the customer

It is calculated as the product of three quantitativeratings, each one related to the effects, causes, andcontrols:

Effects Causes Controls

RPN = Severi y X Occurrence X De ec ion


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Investigate & FixSpecial CausesDefinition of RPN Terms

Severity (of Effect)Severity (of Effect)-- importance of effect on customer

requirements - could also be concerned with safety andother risks if failure occurs (1=Not Severe, 10=VerySevere)

Occurrence (of Cause)Occurrence (of Cause)-- frequency with which a givencause occurs and creates a failure mode. Can

sometimes refer to the frequency of a failure mode(1=Not Likely, 10=Very Likely)

Detection (capability of Current Controls)Detection (capability of Current Controls) -- ability ofcurrent control scheme to detect or prevent:

the causes before creating failure mode

the failure modes before causing effect

1=Likely to Detect, 10=Not Likely at all to Detect


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Investigate & FixSpecial Causes"E ample" Rating Scale

Ra ing Severi y o E ec Likelihood o Occurrence Abili y o De ec

10 Hazardous without warningVery high:

Can not detect

9 Hazardous with warningFailure is almost inevitable

Very remote chance of detection

8 Loss of primary functionHigh:

Remote chance of detection

7

Reduced primary function

performance

Repeated failures

Very low chance of detection

6 Loss of secondary functionModerate:

Low chance of detection

5Reduced secondary function

performance

Occasional failuresModerate chance of detection

4Minor defect noticed by most

customersModerately high chance of detection

3Minor defect noticed by some

customers Low:High chance of detection

2Minor defect noticed by

discriminating customers

Relatively few failuresVery high chance of detection

1 No effect Remote: Failure is unlikely Almost certain detection

De ec ion is ypically

assumed o imply

ac ion can be aken


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Investigate & FixSpecial CausesQuiz!

Sev Occ Det Result Acti

Take 5 mi utesto ill i the results a d what action

should betaken. Be prepared to discuss results.


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Investigate & FixSpecial CausesFMEA Form - Initial Assessment

Pr

cess

te /I tPote tial ail re Mode Pote tial ail re

ects

Pote tial a ses

O

rre t ontrols

P

N

Actions

ecommended

What is the

pro

ess step/

Input under

in

estigation?

In

hat

a

s does the Ke

Input go

rong?

What is the impa

t on the Ke

Output

ariables (

ustomer

equirements) or internal

requirements?

o

! "

e#

ere

isthe

effe

$

t

tothe

$uso

tmer?What

auses the Ke

Input to

go

rong?

o

! oftendoes

$ause

orFMo

$

$ur?What are the existing

ontrols and

pro

edures (inspe

tion and test)

that pre

ent eith the

ause or the

Failure Mode? Should include an

SOPnumber.

o

! !ell

$

a

n

%ou

dete

$t

$auseo

rFM?

What are the a

tions

for redu

ing the

o

urran

e of the

ause, or impro

ing

dete

tion? Should

have actions only on

hi & h PN's or easy

ixes.

0

0

0


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Investigate & FixSpecial CausesFMEA Methodology

Two major approaches:

Starting with Cause & E ect Matrix

Starting with FMEA directly from the Process Map

We will e plain the approach using the C&E matri ,

though both approaches are very similar

Spreadsheet tools have been prepared to assist youin the preparation of the FMEA


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Investigate & FixSpecial CausesFMEA Methodology - Starting with

C&E Matri

AdvantageAdvantage:: The Cause & Effect Matri assists theteam in defining the important issues that the FMEAshould address by helping to prioritize importantcustomer requirements

Process inputs that could potentially impact theserequirements

Prioritizing the Key Process Inputs according totheir impact on the Output variables (We want tofocus on Inputs that highly impact a large number

of Outputs first The C&E Matri also provides quantitative output

that can be used in the determination of thespecific severity ratings for the ne t stage of theFMEA process


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Investigate & FixSpecial CausesFMEA - Step by Step

1. For each process input, determine the ways in which the

input can go wrong (failure modes)2. For each failure mode associated with the inputs, determine

effects of the failures on the customer

Remember the internal customers!

3. Identify potential causes of each failure mode4. List the Current Controls for each cause or failure mode

5. Create Severity, Occurrence, and Detection rating scales

6. Assign Severity, Occurrence and Detection ratings to eachcause

7. Calculate RPNs for each cause

8. Determine recommended actions to reduce high RPNs

9. Take appropriate actions and recalculate RPNs


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Investigate & FixSpecial CausesProcess Mapping E amples

Manu acturingManu acturing

Outputs Outputs

TV of Mi -QualityCheckaround

e trusion

TV of Mi -QualityCheckarounde trusion

Surface Area

Pore Volume

Appearance

pH Temp Specific Gravity Clarity

Appearance(Color,Wetness)

Appearance(Color)

PhysicalChemicalProperties

Cycle Time(plugging)

Zone 3 Temp

Mixing

Water andMetals

Preparation

Extrusion

E trudethrough die

Dryer

Calciner

Materialdrying, surface

area issues

NADM

SolutionPreparation

Impregnation

Metalsaddition

Fluid Bed

DryerFinal

preparation /appearance

issues

Total Rate CMi er Speed CAl2O3 Qual URec Comp U

E t Rate C

Die Wear U

E t RPMs C

Die Change U

Temperature C

Rot speed C

Draft C

Feed Rate C

Drying air U

Inputs Types Inputs Types

Nitric Acid CH2O2 CWater CADM CHold Time U

Agitation C

Phos Acid C

Nozzle Type C

Spray Time C

Water C

Moly C

Nickel C

Base C

Temperature C

Rate C

Air Flow C

Res Time C


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Investigate & FixSpecial CausesC&E Matri E ample

This is the C&E Matri for the previous Manufacturing

Process Map with the Key Inputs sorted by the Total ScoreRating of Importance to ' ustomer 8 8 4 9 10 4 8 8

1 2 3 4 5 6 7 8

P

lugging

C

ycleTime

Length

D

istribution

P

orosity

D

istribution

C

olor

C

atalyst

P

erformanc

M

oly

D

istribution

P

ellett(withi

&

between)

D

ust/Fines

C

ontent

%

Moly&%

N

ickel

Total

Process tep Process Input

Impregnation Moly 9 0 0 3 9 3 9 9 345

NADM ADM 9 0 0 1 9 3 9 9 327

Impregnation Two Step / One Step Process 9 0 0 3 9 9 9 3 321

Impregnation Base 3 9 9 0 9 3 3 1 266

Impregnation Order of Addition 3 0 0 3 9 9 3 3 225

Impregnation Water 3 0 0 9 0 9 9 0 213

Impregnation Nickel 1 0 0 9 3 0 0 9 191NADM Nitric Acid 9 0 0 0 3 9 3 1 170

NADM Hydrogen Peroxide 9 0 0 0 3 9 3 1 170

NADM Water 9 0 0 3 1 3 3 3 169

NADM Temperature (Steam Inj) 9 0 0 3 1 3 3 3 169

Fluid Bed Dryer Temp 3 0 0 9 3 0 1 0 143

Mixing Al2O3 Quality 1 9 9 0 0 0 3 0 140

Mixing Recycle Rate 1 1 1 0 1 3 3 9 138


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FMEA Worksheet

Be ore we move to the example lets look at an FMEA worksheet

The in ormation on this sheet is trans erred directly to the FMEA orm

The purpose o this worksheet is to ocus the team on the FMEA inputs

and not on scoring

The scoring should be done after the basic inputs have been madeThe scoring should be done after the basic inputs have been made

FMEA Worksheet.XLSFMEA Worksheet.XLS

Process

Step KeyProcess Input

Failure odes -hatcan o

rong? Effects Causes CurrentControls


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1. For Each Process Input, Determine theWays in Which the Input Can Go Wrong(Failure Modes)

We will first deal with the Moly Flow Rate input variable.

ro ess

tep nput

Failure ModesWha t an o

wron ? ffe ts auses

urrent

ontrols

Impregnation

Moly Flo rate

Moly Flo rate is too

high


lo

FMEA Step 1


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2. For Each Failure Mode Associated withthe Inputs, Determine Effects

These effects are internal requirements forthe next process

and/orto the final customer

rocess

tep/ nput

Failure odeshat can go

rong ffects Causes

Current

Controls

Impregnation

Mol Flowrate

Mol Flowrate is too

highff pec Material

lugs dr er

Mol Flowrate is too

lowff pec Material

FMEA tep 2


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3. Identify Potential Causes of Each FailureMode

In most cases, there will be more than one Cause for a Failure

Mode but well keep it simple forthis exercise

Process

Step Input

Failure Modeshat can go

wrong Effects Causes

Current

Controls

I pregnation

Moly Flo rate


highff Spec Material eigh Cell Failure

Plugs dryer eigh Cell Failure

Plugs dryer perator Error


loff Spec Material eigh Cell Failure

ff Spec Material perator Error

May elect to list both effects on a single line since they

relate to a single cause, and reduce a line in the table.

FMEA Step 3


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5. Create Severity, Occurrence, and Detection

Rating ScalesExample Rating ScaleRating Severity ofEffect Likelihood ofOccurrence Ability to Detect

10 Hazardous without warningVer hi h:

Can not detect

9 Hazardous with warningFailure is a lmost inevitable

Very remote chance of detection

8 Loss of primary functionHi h:

Remote chance of detection

7Reduced pr imary function

performance

Repeated failuresVery low chance of detection

6 Loss of secondary functionModerate:

Low chance o f detection

5Reduced secondary function

performance

Occasional failuresModerate chance of detection

4Minor defect noticed by most

customersModerately high chance of detection

3Minor defect noticed by some

customers Low:High chance o f detection

2Minor defect noticed by

discriminating customers

Relatively few failuresVery high chance of detection

1 No effect Remote: Failure is unlikely Almost certain detection

FMEA Step 5


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6. Assign Severity, Occurrence and Detection

Ratings to Each Cause

We are now ready to transfer the worksheet input to theFMEA form

Copy and paste the worksheet columns into the appropriate

FMEA form columns

The team then starts scoring each row to compute the RPNvalues

Notes:

You will only use one Severity value

Determine which effect has the highest associated Severity anduse that SEV value forALLALL causes for the related failure mode(Worst Case)

o When combining effects that have the same cause Ne t Slide

FMEA Step 6


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I ti t & Fi


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Investigate & FixSpecial CausesRPN Review

Once you calculate the RPN for each failure mode /cause / controls combination, review the results andlook for insights

Do the gut check - does the Pareto of items makesense?

If not, maybe the ratings given are varying

Determine potential ne t steps:

Data collection

E periments

Process improvements

Process control implementations


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9. Take Appropriate Actions and

Recalculate RPNs

We have recorded the action taken and the impact on the RPN

Notice thatthis is a nice way to track past activities

The FMEA should be re-evaluated by the group as new

recommended actions are identified, completed and recorded

Process

tep nput

Potential

Failure M ode

R

P

N

Actions

RecommendedResp Actions Taken E E

T

R

P

N

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nation1

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step 3 step

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Investigate & Fix


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Investigate & FixSpecial CausesB-326DI FMEA E ample

Prepared by: Glen P. Wieger

FMEA Date (Orig) 5 September, 2002 (Rev) 1

Process Step/Input Potential Failure Mode Potential Failure Effects

S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Item

Number

What is the process

step/ Input under

investigation?

In what ways does the

Key Input go wrong?

What is the impact on the

Key Output Variables

(Customer Requirements)

or internal requirements?

How

Severeisthe

effecttothecusotmer?

What causes the Key Input

to go wrong?

How

oftendoescauseor

FMo

ccur?

What are the existing controls

and procedures (inspection and

test) that prevent either the

cause or the Failure Mode?

Should include an SOP number.

How

wellc

anyoudetect

orpreventcauseorFM?

272

Cation Production -

Filter H2O Flow Flow Too Low

before regen required forspacing, results in

production loss 9

No flow equilization between

vessels 10 None 8 720

283

Cation Production -

Filter H2O Flow Flow Too Low

u

before regen required for

spacing, results in

production loss 9

Lack of DCS control logic to

control flow 10 None 8 720

291

Cation Production -

Filter H2O Flow Flow Too High

u g

run-lengths, early

regeneration resulting in

production loss 6



301

Cation Production -


nequa spac ng o vesse

run-lengths, early

regeneration resulting in

production loss 6



305

Cation Production -


un engt s s ortene ue

to bottom layer of resin

breakthrough, resulting in

production loss 6



315

Cation Production -


u g u

to bottom layer of resin

breakthrough, resulting in

production loss 6



111

Cation Production -

Resin Condition

Insufficient exchange

capacity

oss o exc ange capac ty -results in short run lengths,

loss of production, higher

regen costs 7

Improper regeneration (over

time) 8 DCS control 7 392

Building 326 DI PlantUtilities Division Six Sigma Team

Process or Product Name:

Responsible:


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Investigate & Fix


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Investigate & FixSpecial CausesApproaches to FMEA

Approach One (C&E Matri Focus)Approach One (C&E Matri Focus)

Start with key inputs with the highest scores from the C&EMatri analysis

Fill out the FMEA worksheet for those Inputs

Calculate RPNs and develop recommended actions for thehighest RPNs

Complete the Process FMEA for other Inputs over time

Approach Two (Customer Focused)Approach Two (Customer Focused)

Fill out the failure mode and effects columns of the worksheet.Copy to FMEA form and rate Severity.

For High Severity Ratings, List causes and rate Occurrencefor each Cause

For the highest Severity * Occurrence Ratings, evaluatecurrent controls

For Highest RPNs develop recommended actions

Investigate & Fix


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Investigate & FixSpecial CausesApproaches to FMEA Continued

Approach Three (Comprehensive)Approach Three (Comprehensive)

Good approach for small processes Fill out the FMEA worksheet beginning with the

first process step and ending with the last

Score SEV, OCC and DET for all causes

Develop recommended actions for highest RPNs

Approach Four (Super Focused)Approach Four (Super Focused)

Pick the top Pareto defect item (Damaged

Components) or Failure Mode (Variability inTemperature)

Focus the FMEA process on only that defect orfailure mode

Purpose: To kill that failure mode

Investigate & Fix

FMEA Overview


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Process

Step/InputPotential Failure Mode Potential Failure Effects

S

E

V

Potential Causes

O

C

C

Current Controls

D

E

T

R

P

N

Actions

Recommended

0 0 0 0

0 0 0 0

0 0 0 0

0 0 0 0

0 0 0 0

What

is the

Input

WhatWhat

can gocan go

wrongwrong

with thewith the

InputInput

What canWhat can

be donebe done

What isWhat is

the Effectthe Effect

on theon the

OutputsOutputs

What areWhat are

thethe

CausesCauses

How canHow can

these bethese be

found orfound or

preventedprevented

HowHow

BadBad

HowHow

OftenOften

HowHow

wellwell

FMEA Overview

Investigate & Fix

S C A P C id ti


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Investigate & FixSpecial CausesS.C.A.P. Considerations

1) A single joint is above UCL or below LCL2) A run of 8 above or below CL

Target

Time

2) Chronic Problems

Bad

Better

Time

1) Sporadic Problems

Note: S.C.A.P. may need to be specific to the type of instability

Investigate & Fix

A Typical S C A P


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est gate & xSpecial Causes

Plot Data on Control Chart

Recheck Lab Analysis

Control

Chart

Signal?

RecheckValue InsideControl Chart

Limits?

Adjust Process Variable (Knob)

Wait for Another Sample

Ne tSample ValueInside ControlChart Limits?

Delete Original

Value

Replace With

New Value

No

Yes

Yes

No

YesNo

A Typical S.C.A.P.

Investigate & Fix

A S t d S C A P


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gSpecial CausesA Suggested S.C.A.P.

Plot data on Control Chart

Control

ChartSignal?

Is

Adjustment

Process

Variable

Appropriate?

Adjust Process

Variable and Collect

Another Sample as

Soon as Appropriate.

Stability

Restored?

Continue

to

Monitor

Is

Another

Adjustment

Called for?

Document

Actions

&

Results

Process Operating Conditions

Equipment Failure

Raw Material Change

Procedure Deviation

All OK?

Correct Process and

Collect Another

Sample as Soon as

Appropriate

Stability

Restored?

Continue

to

Monitor

Last

Resort

Adjustments

Document

Actions

&

Results

Continue

to

Monitor

Document all

Actions, Results

and

Additional

Observations

Preventive

Action

Documentation

Documentation

Corrective Action

Investigative Action

Documentation

Compensating Action

No

YesYes

aboratory

ontrol

trategy

Yes Yes

Yes

NoNo

No

No

No

Yes

Yes

Production

Control

Strategy


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Investigate & Fix

SC


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7-61

gSpecial Causes

%9835 Control Strategy for PM-9877-C Process

Reason for low % 9835, if found:

Action taken:

Out-of-ControlCondition

PossibleCauses

Actionto Take

InvestigativeResults

InvestigatedBy

%9835 abov e uppercontrol limit for 1

1. Incorrectcalculations

1. Recheck all calculations1. Calculations Correct? ____Yes ____No_________

batch or above target

f or 8 consecutiv ebatches

2. Not enoughPM-939 added.

2. a. Check the batchrecords.

b. Check the scalesf or accuracy .

c. Check valves incharging line.

d. Check packinggland on Milroy alpump for leaks.

e. Check packing glandon autoclave agitator.

2. a. Amount of PM-939 added ______lbs.

b. Scales are accurate? ____Yes ____No

c. Any v alves leaking? _____Yes ____No

d. Packing gland leaking? ____Yes ____No

e. Agitator packing gland leaking?

_______ Yes _______ No

_________

_________

_________

_________

_________

Batch Number

__________

3. Overcharge ofPM-9835.

3. a. Check the batchrecords.

b. Check the scalesf or accuracy .

3. a. Amount of PM-9835 charged?_____lbs

b. Scales are accurate? ____Yes ____No

_________

_________

4. Assay ofPM-9835 is lowor high.

4. a. Check the assayof the PM-9835used in computer.

b. Was thisfirst batchaf ter changing lotsof PM-9835?

4. a. PM-9835 assay _____% (in computer)

PM-9835 assay _____% (f rom vendor)

b. New lot of PM-9835? ____Yes ____No

_________

5. Change inPM-1530cataly st quality.

5. a. Check if catalys tdrum was changedf or this batch.

b. Sample cataly st.

5. a. New cataly st drum? ____Yes ____No

b. 4-ounce sample. Hold f or tech staf f ._________

6. Incorrecttemperatureand/or pressureconditions.

6. Check the batchrecords and charts.

6. a. Maximum temperature _______C

b. Maximum pressure ________psig

c. Addition time ______hrs ______min

_________

_________

7. Recorders out of calibration.

7. Hav e the recorderschecked f or propercalibration.

7. Were the recorders properly calibrated?

_______ Yes _______ No_________

8. Laboratoryerror.

8. a. Ask lab whetheranaly sis wasrepeatable.

b. Re-sample batchand hold sample

f or tech staff .

8. a. Laboratory t est run in duplicate?

_______ Yes _______ NoIfno, request that sample be re-run.

Recordbothv alues on batch record.b. 4-ounce sample. Hold f or tech staf f .

_________

S.C.A.P.CheckSheet

Example

Investigate & Fix

K l d /S t R i t


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gSpecial CausesKnowledge/Systems Requirements

for a S.C.A.P.Compensating Action

Criteria for judging if compensating action is appropriate. What process variable is to be adjusted?

Required effect of process variable adjustment.

Amount of adjustment to obtain the required effect.

Criteria for judging if stability has been restored.

Investigative Action Standard (Required) Process Operating Conditions.

Equipment failures signals.

Raw material analysis techniques.

Well-defined procedures.

Corrective Action Well-defined procedures for correcting any deviation

detected in the Investigative Action.

Last Resort adjustment procedures.

Criteria for judging if stability has been restored.

DocumentationProcedures/Systems for documenting actions, results

and additional observations.

Procedures, Lists, charts for accumulating actions,

results and additional observations.

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Special Causes

Control Charts provide information, I.e., when to take

action and when not to take action.

People must know what action to take. Actions need to

be standardized for all people.

People control the process, not the control charts.

Investigation of Assignable Causes and the correction/

prevention of problems should never end.

Control Charts and the S.C.A.P. need to be

reviewed periodically and updated as needed.

Process Control is the responsibility of Operations.

Control Charts need to be in the hands of the people

who control the process.

S.C.A.P.

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Special Causes

StatisticalProcess

Control

Use SPC toMaintainCurrentProcess

Collect &Interpret

Data

SelectMeasures

DefineProcess

IsProcess

Capable?

Improve

ProcessCapability

IsProcessStable

?

Investigate &Fix Special

Causes

No

Yes

No

Yes

Statistical Process Control (SPC)is a collection of activities:

Selection of appropriate processmeasures

Collection of process dataGraphical analysis of dataAnalysis of process stabilityUse of data to investigate and fix

special causes in a continuousimprovement cycle

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Special Causes

E ercises

1.) Your Catapult Team should complete page 10 of theCatapult Process handout.

Limit yourselves to 30 minutes for this e ercise.

7-improving unstable processes

Documents