Critical To Quality

Report
Critical To Quality
Using the voice of the customer to
measure Quality
1
7/7/2015
Jina Jayanetti
Translate Consumer Requirements
to Part CTQ Characteristics
Step 1 - Understand Consumer & Technical Requirements
Step 2 - Translate Technical Requirements to Part CTQ
Step 3 - Determine how capable we are of meeting requirements
Understand
Consumer Requirements
Customer Expectations
Define
Technical Requirements
Establish measurable testing
method
What Parts are Affected?
Determine parts effected and
CTQ Characteristics
(How are they affected?)
Are we capable?
Establish dimension of part that
effect the Technical
requirements (Y)
Y (Output)
X’s (Input)
Measure parts; establish
capability, calculate Z-score
Driving decisions with data, not opinion
7/7/2015
Jina Jayanetti
2
Critical To Quality
(CTQ) Flowdown
Voice of
Customer
Function
Parts
Dimensions
Capability
Match Capability vs. goal
Launch
7/7/2015
Jina Jayanetti
3
Key Terms
• KPIV
– Key process input variable
– Associated with the X’s
• KPOV
– Key process output variable or Customer requirement
– Associated with the Y’s
y  f ( x1 , x2 ,..., xk )
Understand the X’s - control
the Y’s
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7/7/2015
Jina Jayanetti
A Grate Example
CTQ Flow Down In action
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7/7/2015
Jina Jayanetti
CTQ Flow Down
Marketing
Voice of the Customer
C.U.
Sales
Engineering
MCS
Pots should be stable on the surface
Grate Fingers and Base should be flat and parallel within
0.040”
Technical Requirements
Part Drawings
CTQ Characteristics
Customers
Grate and Main Top
Finger Flatness
Target=0 USL=.040”
Base Flatness
Target=0 USL=.040”
Top Flatness
Target=0 USL=.040”
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7/7/2015
Jina Jayanetti
Capability and Z-score
Cp
Answers the question “Are the specifications matched to the variation in the process?”
Formula:
Upper Spec - Lower Spec / 6*Std Dev
Cpk
Answers the question “How well does the process meet the specification?”
Formula:
Minimum Lower Cp & Upper Cp
Lower Cp = Mean - Lower Spec / 3* Std Dev
Upper Cp = Upper Spec - Mean / 3*Std Dev
(Pp and Ppk are calculated the exact same way, except for the standard deviation number.
They use an “inflated” standard deviation to account for changes over time.)
How does this relate to Z-score?
Z short term = 3 * Cpk
Status -
7/7/2015
Z long term = 3 * Ppk (or
“Green” if Ppk > 1.33
“Yellow” if 1.33<Ppk < 1.0
“Red” if Ppk < 1.0
Jina Jayanetti
(Zlt > 4.0)
(4.0 < Zlt < 3.0)
(Zlt < 3.0)
Zst - 1.5)
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Scorecard Inputs
Supplier Part Number
Critical Characteristic
PI
7512P123-60 Grate
Dimension Finger Flatness
Dimension
Base Flatness
Tolerance
(+/-)
LSL USL Mean
0.04
0
Data
Type Responsible
Jerry Place
0.04 0.024 0.003
B
0.04
0
0.04 0.036 0.009
Data Type Codes:
A=Expert Opinion
B=Similar Process
C=Existing Part
D=1st Shot from Tooling
E=PPAP
F=Production Part
7/7/2015
Jina Jayanetti
Std
Dev
B
8
Scorecard Calculations
Cpk Ppk
Supplier Part Number
Critical Characteristic
PI
7512P123-60Grate
Dimension Finger Flatness2.22 1.37
Dimension
Process
Capability
Base Flatness 0.74
Z
PPM
2
3
4
5
6
308,537
66,807
6,210
233
3.4
0.11
ZLT
Status
4.10
Green
0.34
Red
Action
Review with Supplier; investigate
opportunities to reduce variation
Status Green if Zlt>=4.0
Yellow if 4.0<Zlt < 3.0
Red if Zlt < 3.0
Defects per
Million
Opportunity
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7/7/2015
Jina Jayanetti
Total Product Delivery (TPD)
Concept to Consumer
Concept
Generation
Concept
Feasibility
Development &
Implementation
Volume
Production
Transition
Critical To Quality Flowdown (CTQ)
Changes from
Other Areas
Product Change
Request (PCR)
Product
Innovation
Process (PIP)
Marketing Introduction Process (MIP)
Product Development Process (PDP)
Gate Review
Gate Review
Gate Review
Design for Six Sigma Tools
• Pugh Concept
Selection
• CTQ Flowdown
• QFD
• Concept Design
• Design FMEA
• Measurement Systems
Analysis
• Capability Assessment
• Statistical Tolerancing
• Design for Manufacture
• Hypothesis Testing
• Design of Experiments
• Response Surface Methods
• Robust Design Techniques
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•
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•
•
•
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Process Mapping
Process FMEA
Measurement Systems Analysis
Capability Assessment
Statistical Tolerancing
Design for Manufacture
Hypothesis Testing
Design of Experiments
Robust Design Techniques
Control Plans
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Measurement Systems Analysis
Multi-Vari Studies
Capability Assessment
Empirical Tolerancing
Hypothesis Testing
Design of Experiments
Robust Design Techniques
Reliability Assessment
Control Plans
Process Control Methods
QFD / CTQ Flowdown
• Identify Voice
of the customer
• Look for knowledge
of technical
requirements
(collect tribal
knowledge)
7/7/2015
• Translate VOC into
Technical Requirements
• Identify the Critical
Characteristics that
contribute to the
Technical requirements
• Measure Process
Capability for each
Critical Characteristic
• Compare Capability
(Ppk) to Cp and
determine status
Jina Jayanetti
• Critical Characteristics
verified and control
plans/data collection
plans developed
• Critical Characteristics
verified with
production data and
control plans/data
collection plans in place
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CTQ What it is, What it is Not
• What it is
– Brings disciplined approach to a Quality score
card that measures quality prior to product
launch
– Identifies quality issues
• What it is not
– Does not correct quality issues
– A replacement of sound technical judgment.
– A replacement of sound financial discipline.
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7/7/2015
Jina Jayanetti
Key Findings
• Current product drawings require deeper
detail specifications.
• Beginning of the learning curve on process
capability and control.
• Create a closer relationship with
departments that provide VOC information.
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7/7/2015
Jina Jayanetti

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