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six sigma presentation BBs and MBBs
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1
Welcome to
DMAIC
for BBs & MBBs
2
• I = Innovators• CA = Change Agents• P = Pragmatists• S = Skeptics• T = Traditionalists
It’s a Continual Wave, Skeptics and Traditionalists have to be convinced that they only have two choices:
• either get off the beach, or
• Get Wet!
10%
20%
40%
20%
10%I CA P S T
The Five Year Cultural Change Curve
Scale of Perceived RiskLittle Risk Perceived
Large Risk Perceived
• Innovators inspire Change Agents• Change Agents convince Pragmatists through clear
business case, with data• Skeptics have to see it in action • Traditionalists value the status quo above all else
3
The 12-Step Process
Process Capability Y, XCapability IndicesY, XDetermine Process Capability
11
Proposed SolutionFactorial DesignsXDiscover Variable Relationships
8List of Vital Few X’sDOE-ScreeningXScreen Potential Causes7
Control
Piloted Solution SimulationY, XEstablish Operating Tolerances
9
MSAContinuous Gage R&R, Test/Retest, Attribute R&R
Y, XDefine & Validate Measurement System on X’s in Actual Application
10
Sustained Solution Documentation
Control Charts, Mistake Proofing, FMEA
XImplement Process Control12
Improve
Prioritized List of all X’sProcess Analysis, Graphical Analysis, Hypothesis Tests
XIdentify Variation Sources6
Improvement Goal for Project Y
Team, BenchmarkingYDefine Performance Objectives
5
Process Capability for Project Y
Capability IndicesYEstablish Process Capabilities
4Analyze
Data Collection Plan & MSA Data for Project Y
Continuous Gage R&R, test/Retest, Attribute R&R
YMeasurement System Analysis
3
Performance Standard for Project Y
Customer, BlueprintsYDefine Performance Standards
2Project YCustomer, QFD, FMEAYSelect CTQ Characteristics1
MeasureHigh Level Process MapDefine Process MapCApproved CharterDevelop Team CharterBProject CTQ’sIdentify Project CTQ’sA
DefineDeliverablesToolsFocusDescriptionStep
4
Iterative Process
Steps A,B,C
Steps 1,2,3
Steps 4,5,6Steps 7,8,9
Steps 10,11,12
5
Problem statement
Project Y Magnitude Impact
Using Statistics to Solve Problems
Practical Problem
Statistical Problem
Statistical Solution
Practical Solution
D M A I C
Characterize the process Stability Shape Center Variation
Root cause analysis Critical X’s
Measure the influence of the critical X’s on the mean and variability Test Model Estimate
Verify critical X’s and ƒ(x)
Change process
Control the gains Risk
analysis Control
plans
Data Integrity MSA Brainstorm
potential X’s Sampling plan
Collect data
Capability ZBench ST & LT
6
Practical & Statistical Problem
• Look at Scale of Scrutiny and / or Measurement System Resolution
• Check Spread & Center Vs. Specifications & Target• Look at Histogram, Boxplot, Normality
Plot, and Basic Statistics with Specs superimposed
• Check Process Capability Relative to Specifications• Stat>Tables>Tally>Cumulative % to get
Yield on continuous data
• Stat>Table>Tally>Counts on discrete data for Yield
• State the Problem as one of Spread and/or Center
• State the Process Capability
7
The Goal of Six Sigma
To reduce the variation that the Customer feels from our process, centered around an appropriate
mean or target, and within specification limits as defined by
the Customer.
Process Capability = f(Spread, Center, Specifications)
8
Selecting ProjectsWhen selecting a project, consider these issues:• Process–select a low-performing process that has high
impact on CTQs. A significant gap exists between customer requirements and process performance.
• Feasibility• Don’t try to solve world hunger (too broad, too complex). • Is data available? • How will you close the project? Begin with the end in
mind. • Expect to conclude successfully within 4 to 6 months.
• Measurable Impact In dollars In ROI In defect/cycle time reduction In customer satisfaction
• Resource support within the organization Leadership support is critical for success How great is the support for the initiative? How much resistance is there to change? What is the sense of urgency? Resource and Team Members have the skills and
capabilities to support multiple teams and are dedicated.• Project interactions
Multiple teams affecting process Changes planned for the process (e.g., technology) MGPP
9
The Levels of a CTQ
• Level #1: Expressed Customer Need • High Level from VOC
• Level #2: CTQ Characteristic• WHAT you will measure• Effectiveness v. Efficiency• Goodness v. Timeliness
• Level #3: CTQ Metric or Project Y• HOW you will measure it.• A formula or the categories• e.g. Y = End Date - Start Date• e.g. Y = Dissatisfied, Satisfied,
No Opinion
10
Project Y / Defects
Project Y =
How we Measure the Type of Error
Unit (Loan, Day, App, Transaction)
Error Types:• Not Done (Percentage per period)• Done Wrong (How Wrong?)• Done Early and/or Late (How Late/Early?)
DPO = Defects / [Units x Opp/Unit]= D / [U x O] = D / Total
Opps
Defect = Units that fail to meet Customer Specifications
11
VOC Results and CTQ Drill down tree.
CTQ1:Y=Defect =
Business Y orLevel 1 CTQ: VOC
Level 2 CTQ:Responsiveness
Level 2 CTQ:Competitiveness
Level 2 CTQ:TechnicalPerformance
CTQ2:Y=Defect=
CTQ3:Y=Defect=
CTQ4:Y=Defect=
CTQ5:Y=Defect=
CTQ6:Y=Defect
Customer:
Level 2 CTQ:On timeDeliverables
Level 2 CTQ:Accurate &CompleteDeliverables
Important To Our Customer
Single CellProjects
Process-Based Projects
CTQ
Pro
ject
s
Con
trol
labl
e B
y U
sProcess 4
Process 1
Process 2
Process 3
Yellow indicates thisspecific project path
Determining the Project Y
Drill Down Tree
QFD or Detailed “AS IS” Process Map and/or FMEA on Current Process
C O P I S
12
Finding Potential X’s
C O P I S
Data Collection Plan
Detailed “AS IS” Process Map and
FMEA on Current Process
ProblemStatement
Measurements Materials Men & Women
MethodsEnvironment Machines
Process
InputVariables
(X’s)
n Key input andprocess measures(X) that trackvariablesidentified in yourproject as keydrivers of ProjectY variables
Output(Y’s)
n Key output measures(Y) from thecustomer’sperspectiveProcess Variables
(X’s)
X X X X
1313
Plan for Data Collection
Data Collection Is The First Step To Understanding The Variation The Customer Feels.
Clarify purpose of data collection
Identify what data to collect
Test and validate measurement systems
Write and pilot operational definitions
Develop and pilot data collection forms and procedures
Establish a sampling plan
Train data collectors
Pilot process and makeadjustments
Collect data
Monitor data accuracy and consistency
Ensure DataConsistencyAnd Stability
EstablishData CollectionGoals
Develop OperationalDefinitions AndProcedures
1 432 Collect DataAnd MonitorConsistency
14
CTQ’s Are The Bridge Between Our Process Output And Customer Satisfaction.
High Level Customer Need from VOC:
Quick Response
Timely ResponseProject Y(Characteristic)
Time from inquiry to resolution of inquiry(Project Y Metric)
5 minutes or less(Target)
Not greater than 60 minutes Specification/ Tolerance Limit)
Established inDefine Phase
Established inMeasure Phase
Established inMeasure Phase
Established inMeasure Phase
CTQ
Any response taking more than 60 minutes(Defect definition)
Established inMeasure Phase
CTQ Elements (Performance Standards)
15
n = f( “delta”variation)
DESn
sp n
n
n
16
Measurement System Analysis (MSA)
Date Study Conducted: Type of Gage R&R conducted:_ Test-Retest (continuous data) Pass?
Standard Deviation < 1/10th of Tolerance _____ Y N
_ Short Form Reproducibility (continuous data) Pass?% Tolerance = 100x5.15xRbar / (d*xTolerance) [ 30%] _____ Y N
_ ANOVA Gage R&R (continuous data)1) Two-Way ANOVA Significant? Part p-value _____ Y N Oper p-value _____ Y N Oper & Part p-value _____ Y N
Pass?2) % Tolerance [ 30%] _____ Y N3) % Contribution [ 8%**] _____ Y N4) % Study Variation [ 30%**] _____ Y N 5) # Distinct Categories [ 4**] _____ Y N** Assumes Part-to-Part variation is large, these criteria reverse if each part submitted to the test were the same size.Graphical Diagnosis OK?1) Effective Resolution [Xbar, 50% outside Control Limits] Y N2) Stability [R Chart ”small” ranges, in Control ] Y N3) Consistency within [R Chart, similar patterns by Oper] Y N4) Consistency between [Oper/Part Inter. Plot, close intertwine] Y N 5) Systematic shift [Oper/Part Inter. Plot, consistent difference] Y N
_ Attribute Gage R&R (discrete data) Pass?1) % Repeatability [ 90%] _____ Y N2) % Reproducibility [ 90%] _____ Y N3) % Accuracy [ 90%] _____ Y N
Gage R&R pass? Y NIf no, describe plan for improvement: ______________________________________________________________________________________________________________________________________________________________________________________________
17
The Normal Curve
-3s -2s -1s X +1s +2s +3s
68.26%
95.46%
99.73%
68.26% Fall Within +\- 1 Standard Deviation95.46% Fall Within +\- 2 Standard Deviation99.73% Fall Within +\- 3 Standard Deviation
34.13% 34.13%
13.60% 13.60%2.14% 2.14%
0.13% 0.13%
18
Run Chart p-value Interpretation
Run begins each time the median is crossed
Run begins each time direction changes
P<.05 => Too Few Runs
P<.05 => Too Many Runs
Clusters
Mixtures Oscillations
Trends
19
Process Capability Decision Flow
Six Sigma>Product Report, DPMO, L1 (Input D, U and O)
•Sigma Conversion Table gives ZST
•Z LT = Z ST - Z Shift (1.5)
•Product Report and L1 give Z Bench
•Z Bench = Z ST
•Z LT = Z Bench - Z Shift (1.5)
Note:Z ST = Z LT + Zshift
Z ST = Z Bench-ST
Z LT = Z Bench-LT
Do you have
RationalSubgroups?
Is the Distribution
Normal?
No
Do you have
Continuous Data?
Yes
No
Yes
Use Z Bench-LT only and add 1.5 Shift to get Z Bench-ST
Use Six Sigma> Process Report (Input Data, Specification Limits
and Target as appropriate)
Yes
No Is the S-Chart in-control?
Z Bench-LT , Z Bench- ST
& Z Shift all valid on the Process
Report
Yes
Use Z Bench-LT only and add 1.5 Shift to get Z Bench-ST
No
20
SSBSST SSW
Total WithinBetween
2
11
2
1
2
11
jXijXXXnXijXn
i
g
jjj
g
j
n
i
g
j
ZBench Long-term The Shift Short-termVariation Type ALL Special Common Illustrated by
in time I or Run Chart Xbar Chart R or S Chart by Xs Histogram, Main Effects Plot, Box Plot
Normality Plot Interaction Plot Probability Plot Probability Plot Box Plots
Used to Measurea) Capability Accuracy Precisionb) Total R&R Reproducibility Repeatability
Improve Issue Performance Control TechnologyXs - Factors Vital Few Trivial Many
ANOVA Total X-Factor Levels Errordf nT - 1 g - 1 nT - gMS - Variance SST / (nT - 1) SSB / (g - 1) SSW / (nT - g)StDev Total = LT SE = LT / sqrt(n) sp = ST
Regression The Model The Residuals
DOE Main Effects & Experimental Interactions: Y-hat Error: s-hat
21
Testing Your Discrete X’s
Power >or= .90• X is Statistically Significant, i.e. A possible solution can be develop around this X.
• Cross Tab with other significant X’s to determine if they are correlated.
• Segment by level and remaining X’s to identify secondary effects on variation
• Main Effects / Box Plots indicate likely best settings.
• Fish Bone reasons
• Prioritize reasons according to impact and controllability
• Ask “Why?” till at Root Cause
P < .05 P >or= .05
Power < .90
• Not Statistically Significant and we are “sure” of it.
• i.e. Don’t use as a solution and do not include in any transfer function
• Not Statistically Significant, BUT
• Not enough data to be “sure”
• Get more data OR
• Rely on Subject Matter Experts to determine if this should be part of any solution, THEN
• Test it’s effect in a
• Pilot, or an• Experiment
Run Main Effects and Box Plots with Specifications to determine Practical Significance
22
Using the Six Sigma Process Report, Report 2 Control Chart
StabilityXbar R or S
? Not
Not Stable
Stable Stable
Column to Use
ST LT
NA OK
OK OK
OK OK
Capability Calculation
Xbar chart interpretation may not be reliable since the control limits on the Xbar chart are based on Rbar from the R chart or Sbar from the S chart.
Calculate ZST = ZLT + 1.5 or use the standard method
Shift = ZST - ZLT
Shift will be approximately zero for the data sample.
Unless the period over which the data is collected is a relatively long one, the convention is to assume it will eventually shift and toCalculate ZST = ZLT + 1.5 or use the standard method. This may be overly optimistic!
Check your subgroups to see if they are spaced far enough.
23
Is it Graphically Obvious?Histogram / Normality Plot / Run Chart on the Y
756555453525155
0.065
0.060
0.055
Observation
NC
_LA
TH
E
0.4632 0.5368 2.000049.666750.0000
0.7151 0.2849 8.000038.440036.0000
Approx P-Value for Oscillation:Approx P-Value for Trends:Longest run up or down:Expected number of runs:Number of runs up or down:
Approx P-Value for Mixtures:Approx P-Value for Clustering:Longest run about median:Expected number of runs:Number of runs about median:
Run Chart for NC_LATHE
54321
51.5
50.5
49.5
48.5
47.5
46.5
Oper 50
Dis
t 50
Others
No Beer in Park
Smoking in Q
Price Fast Food
Crowds
Wait Time
18 8 19 43 59274 4.3 1.9 4.510.214.065.1
100.0 95.7 93.8 89.3 79.1 65.1
400
300
200
100
0
100
80
60
40
20
0
Defect
CountPercentCum %
Per
cent
Cou
nt
Pareto Chart for Defects
50403020100
40
35
30
25
Amount ($K)
Cyc
le T
ime
P-Value: 0.713A-Squared: 0.257
Anderson-Darling Normality Test
N: 90StDev: 1.00430Average: -0.0018963
210-1-2
.999
.99
.95
.80
.50
.20
.05
.01
.001
Pro
babi
lity
SRES1
Normal Probability Plot
403530
2
1
0
-1
-2
-3
Fitted Value
Sta
ndar
dize
d R
esid
ual
Residuals Versus the Fitted Values(response is Cycle Ti)
Histograms or Normality Plot / Main Effects Plot / Box Plots on the Discrete Xs
Pareto on the Defect Categories
Scatter Plot X vs Y, Residual Plots for Continuous Xs
201482-4-10
95% Confidence Interval for Mu
8765
95% Confidence Interval for Median
Variable: Profits
4.9120
6.0819
4.5045
Maximum3rd QuartileMedian1st QuartileMinimum
NKurtosisSkewnessVarianceStDevMean
P-Value:A-Squared:
7.6595
7.8086
6.9253
23.5200 10.0950 6.3400 1.5300
-12.6800
1250.218488-3.3E-0146.74886.837315.71488
0.1280.582
95% Confidence Interval for Median
95% Confidence Interval for Sigma
95% Confidence Interval for Mu
Anderson-Darling Normality Test
Descriptive StatisticsLSL Target
201482-4-10
95% Confidence Interval for Mu
8765
95% Confidence Interval for Median
Variable: Profits
4.9120
6.0819
4.5045
Maximum3rd QuartileMedian1st QuartileMinimum
NKurtosisSkewnessVarianceStDevMean
P-Value:A-Squared:
7.6595
7.8086
6.9253
23.5200 10.0950 6.3400 1.5300
-12.6800
1250.218488-3.3E-0146.74886.837315.71488
0.1280.582
95% Confidence Interval for Median
95% Confidence Interval for Sigma
95% Confidence Interval for Mu
Anderson-Darling Normality Test
Descriptive StatisticsLSL Target
P-Value: 0.128A-Squared: 0.582
Anderson-Darling Normality Test
N: 125StDev: 6.83731Average: 5.71488
20100-10
.999
.99
.95
.80
.50
.20
.05
.01
.001
Pro
babi
lity
Profits
Normal Probability PlotLSL Target
P-Value: 0.128A-Squared: 0.582
Anderson-Darling Normality Test
N: 125StDev: 6.83731Average: 5.71488
20100-10
.999
.99
.95
.80
.50
.20
.05
.01
.001
Pro
babi
lity
Profits
Normal Probability PlotLSL Target
SuperDeptGenderEducPrior Yr ExpYrs Em
454440 9 8 7 6 5 4 3 2 1 0Sales
Purchasin
g
Enginee
ring
Advertis
ingMale
Female1210 9 8 7 6 5 4 3 2 1 0191611 9 7 6 5 4 3 2 1 027252221201918151412 9 8 7 6 5 4 3 2 1 0
70
60
50
40
30
Sal
ary-
K
Main Effects Plot - Data Means for Salary-K
24
Variable Attribute
Is your “Y” variable data or attribute data?
Determine what should be tested for:1. a difference in the variation of the different subgroups OR2. a difference in the “centering” of the different subgroups
VariationNon-normalSubgroups
NormalSubgroups
Non-normalSubgroups
NormalSubgroups
“Centering”
Chi-
Square
Binomial
Regression
Correlation
HOV Levene’s
Mood’sMedian
1 Sample T-test
One-WayANOVA
HOV Levene’s
NOTE: Temperature, Cycle Time, and Length
are variables. Operators, Suppliers,
and Customers are not.
2 Sample T-test
Is the input being tested also a variable?
No Yes
Construct a Multi-Vari of the data.
Statistical Test Choices
25
Data Analysis
26
Statistical SolutionTests on Continuous Y & Discrete X’s for Differences
between SubgroupsSPREAD 1 X, 2+ SamplesHOV - LevenesNormal or Non-normal subgroups
Multiple X’s & InteractionsData NinjaUnbalanced or Not Full Rank
DOEBalanced & Full Rank
CENTER1 X, All Subgroups tested are Normal1 Sample t-test1 subgroup to a target
2 Sample t-test 2 subgroups, run Levenes first
One-Way ANOVA2+ subgroups, 1 X
1 X, At least 1 subgroup is Non-NormalMood’s Median2+ subgroup, 1 X
Prospectively Paired Data, testing 1 X while blocking another XPaired t-testMultiple X’s & InteractionsTwo-Way ANOVA2 Xs, Balanced & Full Rank
GLM, Data Ninja2+ Xs, Unbalanced or Not Full Rank
DOE3+ Xs, Balanced & Full Rank
27
Tools Categories
Continuous Y
Discrete Y
Continuous X Discrete XTime Series & Scatter Plots, Residual PlotsGage R&R ANOVA Linear RegressionMultiple RegressionGLMDOEData Ninja
Stratified Histograms & Normality PlotsMain Effects, Interactions & Box PlotsGage R&R ANOVACenter: t-tests, ANOVA, Mood’s Median, GLMSpread: HOV - LevenesDOEData NinjaParetoStratified Control ChartsAttribute R&RChi-Square (Test of Independence and Goodness of Fit) & Confidence IntervalLogistic Regression (Coded Y)DOE (Coded Y)GLM (Coded Y)Data Ninja (Coded Y)
Stratified HistogramsAttribute R&RLogistic Regression (Coded Y)DOE (coded Y)GLM (Coded Y)Data Ninja (coded Y)
28
Synonyms / Definitions
• Y = Response = Dependent Variable = Effect
• X = Factor = Independent Variable = Predictor = Model
• Aliasing = Confounding
• Type I Error = error = False Action = Tampering = Producer’s Risk
• Type II Error = error = No Action = Consumer’s Risk
• DOE Runs = # Experimental Conditions x # Replications
• Variance Inflation Factor (VIF) > 10 means that some X’s are intercorrelated, eliminate one of them.
29
Degrees of Freedom
When Subgroup Size Varies (n j)• dfSSB = g - 1,
• where g = # of subgroups
• dfSSW = nT - g = n1 + … + ng - g
• dfSST = dfSSB + dfSSW = nT - 1
When Subgroup Size is Constant (n)• dfSSB = g - 1,
• where g = # of subgroups
• dfSSW = g(n-1)
• dfSST = dfSSB + dfSSW = (gn) - 1
30
Select DOE design based on purpose (screening or optimization), considering # of factors, Resolution and DES, and create Minitab worksheet.
Sort the DOE, all columns, in Std Order Add a new column titled Exp Con for Experimental
Condition, number it 1 to n where n is the numbers of runs for one replication and repeat the sequence for each replication.
Re-Sort, All Columns - including the new Exp Con column, in Run Order and
Run Experiment in Run Order and do a Run Chart in that order. Do Descriptive Stats
Do Box Plots by each factor and by Exp Con Do Stat<DOE<Analyze Factorial Design on Response
column, Analyze Standardized Residual Plots, including Normality and the Pareto and Session Window.
Check for practical significance by running Stat<ANOVA<General Linear Model on the Response and the Statistically significant Factors and Interactions from the DOE. Repeat until the same set of factors/interactions are repeated as significant.
DOE for Mean Checklist
31
DOE for Variance Checklist Run One Way ANOVA by Exp Con, copy the Mean and
StDev for each Exp Con (place cursor in the Session Window at one corner of the two columns to copy, hold down Alt key, click and drag to highlight both columns, Copy)
Create a new Worksheet and paste the Mean and StDev from One Way ANOVA into the first two columns of the new worksheet, using spaces as delimiters.
Go back to the original worksheet Re-sort it again in Std Order and copy the titles and the first n rows, where n is the numbers of runs for one replication, from the Factor columns and paste into the new worksheet
While in the new Worksheet, Do Stat< DOE< Define Custom Factorial Design on the new factor columns. This will create Stdorder, Runorder, CenterPts, and Blocks columns in the new worksheet.
Do Stat<DOE<Analyze Factorial Design on StDev Do Stat<DOE<Factorial Plots, both Main Effects and
Interactions on both Mean and StDev to look for Trade-Offs and to determine optimal settings.
Document Transfer Functions, Run Confirmation Runs at Optimal Settings
32
Selecting the Appropriate Control Chart
Variable orAttribute Data?*
Defects or Defective
Constant Subgroup
Size?
u p
No Yes
Defects or Defective
c np
Rational Subgrouping
Possible?
I, MR X-Bar &R
Variable(Continuous)
Attribute(Discrete)
No Yes
Defects Defectives Defects Defectives
Defects per Unit
Percentage Defective
Defect Counts
Number of
Defective Units