1 ISI, SQC UNIT, BANGALORE ISI, SQC UNIT, BANGALORE SS SS - - DEFINE PHASE DEFINE PHASE THE MANY FACETS OF SIX SIGMA THE MANY FACETS OF SIX SIGMA Metrics Benchmark Vision Philosophy Method Tool Symbol Goal Value Metrics Benchmark Vision Philosophy Method Tool Symbol Goal Value S I X S I G M A
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
THE MANY FACETS OF SIX SIGMATHE MANY FACETS OF SIX SIGMA
�Metrics
� Benchmark
� Vision
� Philosophy
�Method
� Tool
� Symbol
� Goal
� Value
�Metrics
� Benchmark
� Vision
� Philosophy
�Method
� Tool
� Symbol
� Goal
� Value
S
I
X
S
I
G
M
A
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
WHAT IS THIS SIX SIGMA ?WHAT IS THIS SIX SIGMA ?
• A Philosophy
• A Statistical Measurement
• A Metric
• A Business Strategy
• make fewer mistakes in all that we
do.
• helps gage adequacy of product,
process and services
• A measuring system
• good quality reduces cost
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
SIGMA RATING AND PPM ARE CORRELATEDSIGMA RATING AND PPM ARE CORRELATED
Sigma Rating PPM
2 308,537
3 66,807
4 6,210
5 233
6 3.4
Process Defects per
Capability Million Opportunities
Sigma Rating PPM
2 308,537
3 66,807
4 6,210
5 233
6 3.4
Process Defects per
Capability Million Opportunities
SIGMA RATING A PERFORMANCE MEASURE
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
• TO REDUCE VARIATION
• TO REDUCE DEFECTS
• TO IMPROVE YIELD
• TO ENHANCE CUSTOMER SATISFACTION
• TO IMPROVE THE BOTTOMLINE
THE GOALS OF SIX SIGMATHE GOALS OF SIX SIGMA
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
To get results should we focus on Y or X?
• Y
• Dependent variable
• Output of the process
• Effect
• Symptom
• It is monitored
• X1, X2, …….., Xn
• Independent variable
• Input to the process
• Cause
• Problem
• It is controlled
Y = f(X)
THE FOCUS OF SIX SIGMATHE FOCUS OF SIX SIGMA
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
APPROACH TO DEFINEAPPROACH TO DEFINE
Develop Business
Case and
Team Charter
Develop Business
Case and
Team Charter
Map the
current
process
Map the
current
process
Listen to the
Voice of the
Customer
Listen to the
Voice of the
Customer
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
PREVIEW OF DEFINE STEPPREVIEW OF DEFINE STEP
• The subsequent discussions will take you through
– Selecting a project and drafting a charter
– A basic SIPOC analysis
– Gathering/confirming the “Voice of the Customer”
(Effectiveness goals e.g. On time delivery) and/or the
“Voice of the Business” (Efficiency goals e.g. reduction
of inventory).
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
GOALSGOALS– Understand the organizational context for process
improvement projects.
– Understand how to select a DMAI²C project and be able
to apply the criteria to your own project.
– Know the basic elements of the project charter and be able
to develop a charter for your own project.
– Understand the basics of estimating the business impact of
a project and be able to relate them to your own project.
– Be able to identify key players and stakeholders and
incorporate them into the communication plan for your
own project.
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
ORGANIZATIONAL CONTEXT FOR PROJECTSORGANIZATIONAL CONTEXT FOR PROJECTS
Champions/
Sponsors
Black Belt
Green Belt
Team Members
Master
Black BeltCoordinators
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
COMMON PROBLEMS AND COMMON PROBLEMS AND
RECOMMENDATIONSRECOMMENDATIONS
• Many projects encounter one or more of the following problems:
– Not relevant to customers or to business needs
– Project scope too large; won’t have authority to commit time/resources or to make changes in the process; can’t easily identify starting and ending points
– Relevant data hard to collect or too much data
– Can’t define what a defect is
– Process doesn’t cycle often enough
– Problem written as solution
– Recent changes in the process
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
ELEMENTS OF A PROJECT CHARTERELEMENTS OF A PROJECT CHARTER
– Project Description
– Scope
– Goals and Measures (indicators)
– Expected Business Results
– Team Members
– Support Required
– Expected Customer Benefits
– Schedule
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
QUALITY AND PROCESSESQUALITY AND PROCESSES
– Quality is judged by customers based on the output of a process.
– Focusing on the work of the individual worker will not lead to greatly improved quality.
– To improve quality, the process must be improved.
– Simply focusing on or defining a process is NOT improvement—we have to make changes and use data to show the change really is an improvement.
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
WORK AS A PROCESSWORK AS A PROCESS
– Applies to all kinds of work, whether repetitive in
nature or “one-of-a-kind.”
– Having a high-level view of a process helps to:
• define project boundaries (starting and ending points);
• describe where to collect data.
S U P P L I ER S
C U S T O M E R S
OutputsInputs Process
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
SIPOC EXAMPLESIPOC EXAMPLESuppliers Inputs Process Outputs Customers
Copier
Toner
Electricity
OriginalYourself
Power Company
Office Supply
Company
CopiesManufacturer
Making a
photocopy
You
File
Others
Put original
on glass
Put original
on glass Close LidClose Lid Adjust
Settings
Adjust
SettingsPress
START
Press
START
Remove
originals
and copies
Remove
originals
and copies
Process Steps
Paper
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
TRANSLATING VOC/VOB INTO CTQsTRANSLATING VOC/VOB INTO CTQs
• (CTQ = Critical to Quality)
need
VOC/VOB CTQ Tree
I want
CTQ
CTQ
CTQ
CTQ
CTQ
CTQ
CTQ
CTQ
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
EXAMPLE: CTQ TREEEXAMPLE: CTQ TREE
Need Drivers CTQs
General Specific
Hard to measure Easy to measure
Ease of Operation
and Maintenance
Operation
Low qualification of operator
Easy to setup
(training / documentation)
Digital Control
MaintenanceMTBF
Mistake Proofing
Documentation
Minimum special tools /
equipment required
Modification
Skills and Knowledge
Mistake Proofing
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
APPROACH TO MEASUREAPPROACH TO MEASURE
Collect
baseline
data on
defects
and
possible
causes
Develop a
Sampling
Strategy
Validate
your
measurement
system
using
Gage R&R
Analyze
patterns
in data
Determine
process
capability
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
• What is Data ?
Data is a numerical expression of an activity.
Conclusions based on facts and data are necessary for
any improvement.
-K. Ishikawa
If you are not able to express a phenomenon in
numbers, you do not know about it adequately.
-Lord Kelvin
DATA GATHERINGDATA GATHERING
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
TYPES OF DATATYPES OF DATA
CONTINUOUS DISCRETE
Measurable
e.g. :Length, Temperature
Subjective Assessment
e.g. :Score in a beauty
contest
Countable
e.g. :Number of defects
Data if properly collected
• Least influenced by individual biases
• Could be subject to critical analysis
• Generally beyond language barriers and therefore universal in
expression.
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
WHICH OF THE BELOW ARE CONTINUOUS WHICH OF THE BELOW ARE CONTINUOUS
AND DISCRETE DATA?AND DISCRETE DATA?• Width of sheet
• No. of liners thinned
• Tubes rejected by Go- Nogo Gauge
• Diameter of Piston
• Height of a Man
• Sheet thickness
• Out of 100 sheets the numbers that meet the thickness
4 ± 0.9
• Time taken to process a purchase order
• No. of bugs in a program
ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--MEASURE PHASEMEASURE PHASE
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
WHAT IS THE MEASUREOF CENTRAL TENDENCY OF A SET OF
NUMBERS?
WHAT IS THE MEASUREWHAT IS THE MEASUREOF CENTRAL TENDENCY OF A SET OF OF CENTRAL TENDENCY OF A SET OF
NUMBERS? NUMBERS?
• There are three ways in which Central
Tendency of Numbers can be measured.
• These are the 3 M’s
�MEAN
�MEDIAN
�MODE
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
MEASURES OF DISPERSIONMEASURES OF DISPERSIONMEASURES OF DISPERSION
� The extent of the spread of the values from the
mean value is called Dispersion.
� The measures of Dispersions are– Range (R)– Standard Deviation (s)– Variance (s2)– Co-efficient of Variation (CV)
�Standard deviation is the most commonly used measure of dispersion.
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
• No two things in nature are alike.
• This is also true for manufactured products.
• This dissimilarity between two products for the same characteristic is called variation.
• The variation may be or can be made to be so small so as to make the product SEEM similar.
•When we say that 2 things are similar we actually mean that it is not possible to measure the variation present within the accuracy of the existing measuring equipment.
• Variation between 2 products are compared for SIMILAR features or characteristics.
WHAT IS VARIATION ?WHAT IS VARIATION ?
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
• Variations among pieces at the same
time
• Variations across time
TYPES OF VARIATIONTYPES OF VARIATION
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
GRAPHICAL DISPLAY OF GRAPHICAL DISPLAY OF VARIABILITIESVARIABILITIES
InherentVariability
Assignable Variability
Assignable Variability
TOTAL
VAR I A B I L I T Y
Assignable Variability
Assignable Variability
Aimed Value
CASE I
CASE II CASE III
(Black noise)
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
GENERIC CAUSES OF VARIATIONGENERIC CAUSES OF VARIATION
Machines
Materials
Methods
Measurements
Mother Nature
People
P
R
O
C
E
S
S
PP
RR
OO
CC
EE
SS
SS
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
THE NORMAL DISTRIBUTIONTHE NORMAL DISTRIBUTION
95.46
68.26
99.73-3 -2 +3-1 +1 +2
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
IMPORTANT SPC RATIOS USEDIMPORTANT SPC RATIOS USED
This compares the requirement of the process output vis-a-vis the
inherent variability of the process. Higher value than 1 implies that the
process has got the capability to give the product within the set limits.
LSL x USL
- 3 + 3
s 6
LSL-USL
s 6
Tolerance
process of variation Normal
sticcharacteri ofrange allowable Maximum Cp
========
====
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
This gives us the positioning of the mean vis-a-vis the USL and the relationship between the two.
This gives us the positioning of the mean vis-a-vis the LSL and the relationship between the two.
Cpk - Process Performance Index. This is important
Cpk = Minimum of (Cpu and Cpl) ; for bilateral tolerances
= Cpu ;for unilateral tolerance on upper side i.e..
= Cpl ;for unilateral tolerance on lower side i.e..
X+Y-O
X+O-Y
s3
X-USL Cpu ====
s3
LSLX Cpl
−−−−====
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
• Every possibility of making an error is called an opportunity
• The total opportunities available for an error to take place areNos.Chkd. x Opp
• If there are more than 1 opp. The sigma can be calculated by finding DPMO.
• Knowing DPMO we refer to the Normal Dist. Table to get the Sigma value
• One could inflate the opp. and hence get an enhanced Sigma But the opp.are limited to what exactly is checked for.
E.g. a sheet is checked for thickness, length & width and can berejected for either.Hence the opp. is 3
THE CONCEPT OF OPPORTUNITYTHE CONCEPT OF OPPORTUNITY
DPMO = Defects x 106
Units chkd. x Opp.
DPMO = Defects x 106
Units chkd. x Opp.
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
•Defect : Any non-conformity in a product or service
– e.g. Late delivery or no. of tubes rejected
•Units : The nos. checked or inspected
– 100 deliveries were monitored for being late, no. of units are 100
– 1000 tubes were checked for oversize dia., no. of units are 1000
•Opportunity : Anything that you measure or check for.
– Finished refrigerator is checked for 25 defects at final inspection, the no. of opportunities is 25
A FEW TERMINOLOGIESA FEW TERMINOLOGIES
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE
• This Z value is known as the SIGMA RATING
• Knowing the sigma rating we can establish the rejections that can be expected from the process
• The average, the standard deviation & the specification limits are required to get the sigma rating
• There are 2 kinds of sigma ratings.The short term Sigma & the long term Sigma (to be seen in detail later)
• One should not confuse between the sigma rating & the standard deviation
THE SIGMA RATINGTHE SIGMA RATING
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ISI, SQC UNIT, BANGALOREISI, SQC UNIT, BANGALORE SSSS--DEFINE PHASEDEFINE PHASE