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Exploring and Evaluating the Product Performance – Cost
Design Trade Space
Neal Mackertich & Peter KrausRaytheon Integrated Defense Systems
Global Lean, Six Sigma & Business Improvement Summit
15 October 2008
Copyright © 2008 Raytheon CompanyCustomer Success Is Our Mission is a trademark of Raytheon Company
DFSS
Affordability Producibility
Performance
– Voice of the Customer modeling and analysis an integral part of the Requirements analysis process
– Up-front Architectural trade space evaluation (vs. validation)
– Statistical modeling & optimization of the performance / cost design trade space
– Focused application of DFMA principles and best practices
– Predictable acceleration of product development cycle time using Critical Chain concepts
– Stochastically modeled Integration, Verification & Validation Testing
Design for Six Sigma is a methodology used within IPDS to predict, manage, and improve Performance, Producibility, and Affordability for the benefit of our customers
Design for Six Sigma (DFSS)
Why Explore & Evaluate the Design Trade Space?
• There are significant cost saving opportunities available by exploring the Performance – Cost Trade Space
• Mission Assurance– Increasing our ability to deliver high-performing,
affordable systems
• Enables whole System planning, modeling & analysis – Raytheon as a Joint Battlespace Integrator– Design, management, and performance analysis are
becoming increasingly complex and distributed tasks
• Re-use of technical knowledge, analysis tools, and intellectual capital
Enabling Design Trade Space Exploration & Evaluation through Critical Parameter Management
CPM enables the identification and realization of significant product cost savings opportunities and program risk reductions
X’s
Y’s
Y’sRisk
Opportunity
A methodology for exploring and evaluating the product performance – cost design trade space through the statistical identification, analysis and management of critical parameters.
Critical Parameter Management Flow
■ Identify Critical Parameters
■ Build Design Model / Transfer Function
■ Conduct Statistical Assessment
■ Perform Trade Study Analysis
Identify Critical Parameters
Gain a detailed understanding of the customer value equation, product requirement needs and priorities
Selection based on performance, cost, producibility & schedule criticality
Includes key Systems Technical Performance Measures (TPMs) and their derived requirements
Build Design Model / Transfer Function
Mathematically defines critical parameter as a product characteristic
Typically derived from physical laws, historical data, simulation models or design of experiments / regression analyses
Links ownership to parameters across the product hierarchy
Complete and consistent hierarchy of critical parameters (including transfer functions) originating from Customer needs.
X4
y1
y2
X2X3
X1
Conduct Statistical Assessment
A
B
C
D
E
Y
Y = f (A, B, C, D, E, F,...,M)0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
180
187
194
201
208
215
222
229
236
243
250
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
17
17.6
18.2
18.8
19.4 20
20.6
21.2
21.8
22.4 23
0
0.2
0.4
0.6
0.8
1
1.2
1.4
15
15.8
16.6
17.4
18.2 19
19.8
20.6
21.4
22.2 23
0
0.2
0.4
0.6
0.8
1
1.2
1.4
15
16.5 18
19.5 21
22.5 24
25.5 27
28.5 30
0
0.2
0.4
0.6
0.8
1
1.2
1.4
15
16.5 18
19.5 21
22.5 24
25.5 27
28.5 30
Response
F
G
H
I
J
K
L
M
0
0.05
0.1
0.15
0.2
0.25
15
16.5 18
19.5 21
22.5 24
25.5 27
28.5 30
Design Variables
Allocation/Flow Down
Conduct Statistical Assessment
Certainty is 95.12% from 4.00E+1 to 5.30E+1
.000
.007
.014
.020
.027
0
33.75
67.5
101.2
135
3.75E+1 4.25E+1 4.75E+1 5.25E+1 5.75E+1
G-Sys. Losses -.45
A-Pavg .35
D-Ant. Eff, .35
F-Integ. Eff. .34
J-Rec. BW -.34
B-Ant. Gain .29
H-Tgt RCS .23
C-Ant. Aperture .21
K-Pulse Width -.19
M-Rec. Out SNR -.15
I-Noise Figure -.12
L-Rep. Freq. -.03
-1 -0.5 0 0.5 1
Measured by Rank Correlation
Capability analysis against specified requirements (Scorecard is sortable by % out of spec. / Cp(k))
Prioritize critical parameters for their business opportunity and risk reduction
Identification of statistical drivers that most strongly influence performance and cost
Perform Trade Study Analysis
Trade Studies
Optimize Cost vs. Performance
Perfo
rman
ce (y
)
Cost
Unacceptable Performance
Unaffordable
Optimal Area
Cost (x)
dy/dx
PerformanceThresholdCost
Objective
CostThreshold
PerformanceObjective
Cost / Performance /
ScheduleTrade Space
Understand the cost utility of the existing design margin
Identify alternative design approaches and specifications
Evaluate alternatives for their business return
Implement recommendation and monitor results in order to ensure Mission Assurance
“The Best Design is the Simplest One that Works.” Albert Einstein
Radar Subassembly CPM Case Study
■ High Volume Subassembly■ Mechanical Dimensions Critical to Electrical
Performance
Project objectives:■ Attain Robust Design performance at minimum
production cost.■ Reduce current unit production cost by 30%.■ Aggressively strive for additional cost savings.■ Become a documented, successful design phase
example for others to follow.
Radar Subassembly Tree Structure
Design Interface
03.0
3;
3
00108.006389.0
=−
−=
==
σµ
σµ
σµ
USLLSLMin C
pk
5004003002001000
0.068
0.067
0.066
0.065
0.064
0.063
0.062
0.061
0.060
sn
GW
Dim B
020406080
100
0.059 0.0
60.0
610.0
620.0
630.0
640.0
650.0
670.0
680.0
69 0.07
BinsFr
eq
Dim BUSL(0.064)LSL(0.062)
Data set with outliers removed Histogram of dimension Dim B relative to Specifications
Use Cpk as a metric of ProcessCapability. Note: Six Sigma qualitylevel = Cpk >1.5.
Dimensional Capability Analysis
X Scorecard
Project Name: Date:
Component CTF (X)Spec Owner UnitsCode LSL Nominal USL Mean Std. Dev. Cp Cpk Sample Size
D1 R admin 0.4250 0.4270 0.4290 0.4270 0.0020 0.3333 0.3333 400D10 R admin 0.4020 0.4030 0.4040 0.4033 0.0020 0.1667 0.1167 400D2 R admin 0.4250 0.4270 0.4290 0.4264 0.0023 0.2899 0.2029 400D3 R admin 0.4020 0.4030 0.4040 0.4009 0.0007 0.4762 -0.5238 400D4 R admin 0.0575 0.0595 0.0615 0.0587 0.0012 0.5556 0.3194 400D5 R admin NA 0.0000 0.0010 0.0012 0.0031 NA -0.0162 400D6 R admin 0.4020 0.4030 0.4040 0.4009 0.0007 0.4762 -0.5238 400D7 R admin 0.4260 0.4275 0.4290 0.4271 0.0015 0.3333 0.2444 400D8 R admin 0.4260 0.4275 0.4290 0.4265 0.0008 0.6250 0.2083 400D9 R admin 0.0620 0.0630 0.0640 0.0639 0.0010 0.3333 0.0367 400
System Level DFSS - Critcial Parameter Management (System Total Component Requirement & X Score Card)
Radiator CPM Example 8/16/2006
Design Specification Validation Test Data
Manufacturing Process Capabilities Cpk<0.34
Cpk
-0.8-0.6-0.4-0.2
00.20.40.60.8
11.21.41.6
Dimension
Acceptable
Good
04.2
3
109.0531.0
=
−=
=−=
C
pkσ
µ
σµ
LSLUse Cpk metric to establish relativeelectrical performance.
Histogram of electrical output relative to specification
Response Performance Capability Analysis
Electrical Performance
0
20
40
60
80
Num
ber o
f Obs
erva
tions
LSL
Electrical Response Performance Cpk> 1.66
Max Spec µ σ Cpk-5.84 -3.63 0.35 2.10-5.84 -3.20 0.32 2.69-5.89 -3.03 0.35 2.71-5.95 -2.97 0.41 2.50-6.00 -2.92 0.42 2.43-6.11 -3.01 0.45 2.26-6.22 -3.24 0.52 1.90-6.27 -3.38 0.56 1.73-6.38 -3.36 0.61 1.66-6.44 -3.13 0.62 1.79-6.49 -2.87 0.59 2.04-6.49 -2.48 0.49 2.71-6.49 -2.27 0.45 3.12-6.49 -2.09 0.42 3.51-6.44 -2.01 0.40 3.67-6.38 -2.00 0.39 3.69-6.27 -2.02 0.39 3.56-6.17 -2.05 0.41 3.33-6.00 -2.24 0.42 2.96-5.84 -2.37 0.44 2.58-5.68 -2.69 0.48 2.06
Radar Subassembly Design Trade Study Analysis
• DOE, Regression and Statistical tests of significance identified only one design feature to statistically impact performance.
• Utilized gained process capability knowledge and a statistical understanding of the impact of assigned tolerances on performance to trade low-margin mechanical design tolerance for cost realization opportunities.
• Through a detailed understanding of what drives manufacturing costs, the team was then able to statistically reallocate tolerances to minimize unit production costs.
• Attained Six Sigma plus electrical design performance.
• Reduced unit production costs by 58%.
• Achieved cost savings of >$5M
• Achieved follow-on contract cost reductions >$30M
Radar Subassembly CPM Case Study Project Results