design structure matrix: iteration models · lecture 4 design structure matrix: iteration models...
TRANSCRIPT
9/16/2003
ESD.36J System & Project Management
Instructor(s)
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Lecture 4
Design Structure Matrix: Iteration Models
©2003 Steven D. Eppinger
http://www.dsmweb.org
Prof. Steven D. Eppinger
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- Today’s Topics
Iteration ModelsPlanned vs. UnplannedSequential vs. Parallel
Product Development Process Analysis using DSMIndustrial ExamplesComparing alternative processes
Process Improvement using DSM“Design Modes”Work Transformation ModelCost and Schedule Simulation
Introduce HW2
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Semiconductor Development Example1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
1 Set customer target • x x •2 Estimate sales volumes x • x x •3 Establish pricing direction x • x •4 Schedule project timeline • x5 Development methods x • x x x x6 Macro targets/constraints x x • x x x x7 Financial analysis x x x x x •8 Develop program map x • x9 Create initial QFD matrix x x x x •
10 Set technical requirements x x x x • x11 Write customer specification x x x x x • O O O O O O O O12 High-level modeling x x x x • x x x13 Write target specification x x x x x x x x x • x x14 Develop test plan x x x x x • x15 Develop validation plan x x x x • 16 Build base prototype x x x x x x •17 Functional modeling x x x x x • x x x x x x x x O O O O O O O O O O18 Develop product modules x x x x x x x x x • O19 Lay out integration x x x x x x x x x •20 Integration modeling x x x x x x x • x x x21 Random testing x x • x x x22 Develop test parameters x x x x x x x • x x x23 Finalize schematics x x x x x • x x O O O O O24 Validation simulation x x x x x x x • x x25 Reliability modeling x x x x x • x26 Complete product layout x x x x x • x x27 Continuity verification x x x x x x •28 Design rule check x x x •29 Design package x x x x x • O O O O O O O30 Generate masks x x x x • x O31 Verify masks in fab x x x •32 Run wafers x • x O33 Sort wafers x •34 Create test programs x •35 Debug products x x x x x • O O O O O O O36 Package products x x x •37 Functionality testing x x x •38 Send samples to customers x x x x •39 Feedback from customers x •40 Verify sample functionality x •41 Approve packaged products x x x x •42 Environmental validation x x x x •43 Complete product validation x x x x x •44 Develop tech. publications x x • x x45 Develop service courses x x • x46 Determine marketing name x x x x x • x47 Licensing strategy x x x •48 Create demonstration x x x x x x •49 Confirm quality goals x x x x x •50 Life testing x x x • x x51 Infant mortality testing x x x x • x52 Mfg. process stabilization x x x • O O53 Develop field support plan x x •54 Thermal testing x x x •55 Confirm process standards x • x x56 Confirm package standards x x x x x • x57 Final certification x x x x x x x x x x x •58 Volume production x x x • x59 Prepare distribution network x x x x x x x x •60 Deliver product to customers x x x x x x x x x •
x = Information Flows = Planned Iterations O = Unplanned Iterations • = Generational Learning
Concurrent Activity Blocks
Potential Iterations
Generational Learning
Sequential Activities
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- Two Types of Iteration
Planned IterationCaused by needs to “get it right the first time.”We know where these iterations occur, but not necessarily how much.Planned iterations should be facilitated by good design methods, tools, and coordination.
Unplanned IterationCaused by errors and/or unforeseen problems.We generally cannot predict which unplanned iterations will occur.Unplanned iterations should be minimizedusing risk management methods.
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-Design Iteration
Product development is fundamentally iterative —yet iterations are hidden. Iteration is the repetition of tasks due to the availability of new information.
changes in input information (upstream)update of shared assumptions (concurrent)discovery of errors (downstream)
Engineering activities are repeated to improve product quality and/or to reduce cost.To understand and accelerate iterations requires
visibility of iterative information flowsunderstanding of the inherent process coupling
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-Instrument Cluster Development
Faster Design ProcessFewer planned iterationsPlanned revision cycleNo unplanned iterations
Slower Design ProcessSeveral planned iterationsUsually one unplanned iteration
• •Casing Design • X X Casing Design • XWiring Layout X • X Lighting Details X •Lighting Details X X • Wiring Layout X X •Tooling X X X • Soft Prototype X X X •Hard Prototype X • Testing X •Testing X • Revision X •
• Hard Tooling X X X X X •• •
SupplierDelco
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- Two Iteration Styles
Sequential IterationOne activity is executed at a time.Models assume that probabilities determine the next actions.Signal Flow Graph Model
Parallel IterationSeveral activities are executed at a time.Models assume that rework is created for other coupled activities.Work Transformation Model
A
B
C
B
A
C
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-Stamping Die Development Process
PanelDesign
DieDesign
ManufacturabilityEvaluation
PrototypeDie
ProductionDie
SurfaceModeling
PanelData
VerificationData
SurfaceData
Analysis Results
SurfaceData
SurfaceDataAnalysis
ResultsDie
Geometry DieGeometry
VerificationData
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Signal Flow Graph Model:Stamping Die Development
1 432 5 6
7
8 9 10
Init. Surf.Modeling
Final Surf.Modeling
0.75 z2 z2
z20.25
z1
z0.25 1
z10.1
z30.9
z7Finish0.5
Start
0.75z2
z0 . 5
z3z3
Final Mfg.Eval.
Prelim. Mfg.Eval.-1
Prelim. Mfg.Eval.-2
DieDesign-1
DieDesign-2
DieDesign-3
1
pzt
durationprobability
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Computed Distribution ofDie Development Timing
.10
.20
1 0 2 0 3 0 4 0 5 0 6 0 7 0
.05
.25
.15
0time (days)
probability
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-Comparing Alternative PD Processes
Application:Jet Engine Development
Volvo Aero Corp.
Evaluation of Design Process Alternatives using Signal Flow Graphs
O. Isaksson, S. Keski-Seppälä, S.D. EppingerJournal of Engineering Design, Sept. 2000.
CB+C
C
Process A – No CFD analysisProcess B – Use CFD in evaluationProcess C – Use CFD in design + eval.
B+C
Rework(to be avoided)
Proceed
Design 1
Eval+Test
Design 2
Eval+Test
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-Comparing Alternative PD Processes
E[LT]C
Process A – No CFD analysisProcess B – Use CFD in evaluationProcess C – Use CFD in design + eval.
Prob
abili
ty o
f Com
plet
ion
Completion Time (days)300 400 500 600 700 800
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
E[LT]B E[LT]A
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-Brake System Design Example
**** **
**X **X **
X X **X **X **
X **X X **X X X **X X **X X **
X **X X X **X X **
X X X **X X X **
X X X X **X X X **
X X **X X X **X ** X
X **X X XX X X **
X X **X X ** XX X X **X X X X X **X X X X X **X X X X X X **
X X X X X **X X X X X ** X X
X XX X X X X ** X X X XX XX X X X X ** X X X XX XX X X X X ** X X X
X X X X X ** X X X X X XX X X X **
X X X X ** X XX X X X X ** X XX X X X X ** X
X X X X X ** XX X X X X ** X
X ** XX XX X X X X X X X ** X X X
X X X X X X ** X X XX X X X X X X ** X X
X X X X X ** XX X X X X ** X X X
X ** X XX ** X
X X X X X X X X X **X X X X XX X X X X X ** X X XX X X X X X ** X X
X X X X X ** XX X X X X X X ** X X X X X
X X X X X X X X X X X ** XX X X XX X X X X X X X X ** X X
X X X X X **X X X X X X X **
X X **X X X X X **
X X X X X X X X **X X X X X X X X X **
X X XX X X X **X X X**X X X X X XX ** X
X X X X X X **X X **X X **
X X **X XX X X **X XX X X X X X X X **
X X X X **X X X **X X X X X **
X X X X **X X **X X **
X X X X X X X X X **X X X X X X **
X X X X X **X X X **
X X X X X X X **X X X X X **
X X **X XX X X X X X X X **X XX X X X X X X X X **X XX X X X X X X X **X X X X X X X X X **X X X X X X X X **X X X X X X X X **
X X X X X **X **
X XX X X X X X X **X X X X **
X X X X X X X X X **X X X X X X X X X X X X X **
X X X X X X X X X **X X X X **
105parameters
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Brake System Coupled Block
33 34 35 37 40 44 45 46 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 0433 Knuckle envelope & attach pts ** • •34 Pressure at rear wheel lock up ** x X • •35 Brake torque vs. skidpoint ** x x x x37 Line pressure vs. brake torque ** • x •40 Splash shield geometry—front • ** • • x x • x44 Drum envelope & attach pts • **45 Bearing envelope & attach pts • ** • •46 Splash shield geometry—rear • • ** • •48 Air flow under car/wheel space x x ** x49 Wheel material ** x50 Wheel design • ** •51 Tire type/material • ** •52 Vehicle deceleration rate X X X ** • x •53 Temperature at components x ** • x •54 Rotor cooling coeficient x x • ** x x55 Lining—rear vol and area x • ** x56 Rotor width x x ** x x •57 Pedal attach pts ** x •58 Dash deflection x ** x59 Pedal force (required) x ** • x X x •60 Lining material—rear • ** • x •61 Pedal mechanical advantage x ** x •62 Lining—front vol & swept area x x ** •63 Lining material—front x • ** X x x64 Booster reaction ratio • x x ** •65 Rotor diameter • • • • ** x •66 Rotor envelope & attach pts x **
104 Rotor material x • • • **
• Weakx MediumX Strong
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The Work Transformation Model(Parallel Iteration Model)
AssumptionsAll coupled tasks are attempted simultaneously.Off-diagonal elements correspond to fractions of each task’s work which must be repeated during subsequent iterations.Objective is to characterize the nature of design iteration.
work vector
work transformation matrix
ut +1 = Aut
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Work Transformation Model Mathematics
totalwork
eigenvectormatrix
scalingvector
work transformation equation
total work vector
eigenvalue decomposition
Total work is a scaling of the eigenvectors.
substitution
11 − λdiagonal matrix of terms
ut +1 = Aut
U = utt =0
∞
∑ = ( At
t =0
∞
∑ )u0
A = SΛS−1
U = S Λt
t =0
∞
∑⎛
⎝ ⎜ ⎞
⎠ ⎟ S−1u0
Λt
t =0
∞
∑⎛
⎝ ⎜ ⎞
⎠ ⎟ = (I − Λ)−1
U = S (I − Λ)−1S−1u0[ ]
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Brake System “Design Modes”
0 5 10 15 20 25 30
Rate of Convergence
Design Mode
slower
faster
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-Brake System “Design Modes”
ThermalDesign Mode
First SecondKnuckle envelope & attach pts 0.0157 0.1215Pressure at rear wheel lock up 0.4808 0.0075Brake torque vs. skidpoint 0.4254 0.0435Line pressure vs. brake torque 0.1979 0.0228Splash shield geometry—front 0.1109 0.8328Drum envelope & attach pts 0.0011 0.0141Bearing envelope & attach pts 0.0168 0.1356Splash shield geometry—rear 0.0143 0.0654Air flow under car/wheel space 0.0512 0.5824Wheel material 0.0057 0.0610Wheel design 0.0156 0.1051Tire type/material 0.0731 0.0177Vehicle deceleration rate 1.0000 0.0910Temperature at components 0.1641 0.3224Rotor cooling coefficient 0.1035 0.9598Lining—rear vol and area 0.1479 0.0166Rotor width 0.1043 1.0000Pedal attach pts 0.1843 0.1584Dash deflection 0.3510 0.2265Pedal force (required) 0.7818 0.2317Lining material—rear 0.1765 0.0587Pedal mechanical advantage 0.4193 0.1749Lining—front vol & swept area 0.1669 0.2052Lining material—front 0.4870 0.0417Booster reaction ratio 0.3502 0.0787Rotor diameter 0.1117 0.0463Rotor envelope & attach pts 0.0057 0.0705Rotor material 0.0757 0.3168
Stopping PerformanceDesign Mode
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-Turbine Blade Development Process
Process Improvement Simulations Using the Work Transformation Model
P. Cronemyr, A. Öhrwall Rönnbäck, S.D. Eppinger International Conference on Engineering Design
Munich, August 1999.
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Turbine Blade Development DSM
Existing Process: Different CAD Tools Proposed Process: Common CAD Tools
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- DSM (WTM) Analysis Results
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- Lessons Learned: IterationDevelopment is inherently iterative.An understanding of the coupling is essential.Not everything should be concurrent in concurrent engineering.Iteration results in improved quality.Iteration can be accelerated through:
information technology (faster iterations)coordination techniques (faster iterations)decreased coupling (fewer iterations)
There are two fundamental types of iteration:planned iterations (getting it right the first time)unplanned iterations (fixing it when it’s not right)
Mature processes have more planned and fewer unplanned iterations.
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DSM Simulation QuantifiesCost and Schedule Risk
Task-based project network model using DSM representationEffects modeled:
Probabilistic iteration and reworkLearning effectsStochastic task durations and costsResource constraintsOverlapping tasksRisk-based control of parallel rework
Discrete-event Monte-Carlo simulationLatin Hyper Cube samplingSimulation outputs:
Cost and schedule outcome distributions Budget and deadline risk factors
Two reference papers:“Product Development Process Modeling Using Advanced Simulation”, Soo-Haeng Cho and Steven D. Eppinger, ASME Design Theory and Methodology Conference, September 9-12, 2001.“Modeling Impacts on Cost and Schedule Risks in Product Development”, Tyson R. Browning and Steven D. Eppinger, Working Paper 2001.
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-UAV Concept Study DSM Inputs
Unmanned Aerial VehiclePreliminary Design Activities
Tasks, Durations, Learning Parameters
MIT Lean Aerospace Initiative
2 3 4 5 6 7 8 9 10 11 12 132 0.23 0.5 0.44 0.55 0.5 0.1 0.1 0.3 0.16 0.47 0.48 0.5 0.59 0.5 0.5 0.5
10 0.1 0.5 0.2 0.1 0.411 0.5 0.5 0.5 0.512 0.4 0.5 0.5 0.413 0.5 0.4
2 3 4 5 6 7 8 9 10 11 12 132 0.13 0.3 0.54 0.85 0.1 0.1 0.1 0.3 0.16 0.37 0.88 0.5 0.59 0.3 0.3 0.3
10 0.1 0.5 0.4 0.3 0.311 0.5 0.5 0.3 0.312 0.3 0.5 0.5 0.513 0.9 0.3
Exp. Duration Lear-ID Task Name Opt. Likely Pess. ning
1 Prepare UAV Preliminary DR&O 1.9 2.0 3.0 0.352 Create UAV Preliminary Design Confinguration 4.8 5.0 8.8 0.203 Prepare Surfaced Models & Internal Drawings 2.7 2.8 4.2 0.604 Perform Aerodynamics Analyses & Evaluation 9.0 10.0 12.5 0.335 Create Initial Structural Geometry 14.3 15.0 26.3 0.406 Prepare Structural Geometry & Notes for FEM 9.0 10.0 11.0 0.907 Develop Structural Design Conditions 7.2 8.0 10.0 0.358 Perform Weights & Intertias Analyses 4.8 5.0 8.8 1.009 Perform S&C Analyses & Evaluation 18.0 20.0 22.0 0.25
10 Develop Freebody Diagrams & Applied Loads 9.5 10.0 17.5 0.5011 Establish Internal Load Distributions 14.3 15.0 26.3 0.7512 Evaluate Structural Strength, Stiffness, & Life 13.5 15.0 18.8 0.3013 Preliminary Manufacturing Planning & Analyses 30.0 32.5 36.0 0.2814 Prepare UAV Proposal 4.5 5.0 6.3 0.70
ID 1 2 3 4 5 6 7 8 9 10 11 12 13 1412 1 13 1 14 1 15 1 1 1 1 1 2 16 1 27 1 28 1 19 1 1 1
10 1 1 1 1 111 1 1 1 212 1 1 1 2 213 1 1 114 1 1 1 1 1 1 1 1 1 1 1 1 1
Precedence, Rework Probability, Impact
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-Simulated Schedule of UAV Preliminary Design Process(1 of 1000 simulation runs)
ID \ State D (w /o rew ork) D (w . rew ork) 1 2 3 4 6 7 8 9 10 11 12 13 20 211 2.0 2.02 5.9 5.93 2.9 3.84 8.9 8.95 17.0 19.2 0.5
6 9.0 10.1 2.27 10.3 10.38 7.7 11.59 20.2 21.710 16.3 18.711 15.5 23.8 3.9 0.6
12 14.8 16.7 3.713 34.7 34.714 5.0 5.0
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Results for UAV Preliminary Design Process
570 600 630 660 690 720 750 780 810 840
Cost ($k)
.0
.2
.4
.6
.8
1.0Target
120 126 132 138 144 150 156 162 168 174 180
Schedule (days)
0.0
0.2
0.4
0.6
0.8
1.0Target
COST:PC(un.) ≈ 24%
SCHEDULE:PS(un.) ≈ 91%
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Joint PDF of Paired [C, S] Samples
550600
650700
750800
850900
120130
140150
160170
180
Cost ($k)Schedule (days)
Insight: Bimodal PDF has similar cost but different schedule outcomes.
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550 600 650 700 750 800 850 900120
130
140
150
160
170
180
Cost ($k)
Sch
edul
e (d
ays)
Contour Plot View of Joint [C, S] PDF
Scheduletarget
Budget target
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Comparing Alternative UAV Development Processes
.4 .2.5 .4
.3 .5
.4 .5 .1 .1 .3 .1
.1 .4
.4 .4.5 .5
.4 .5 .5 .5
.1 .5 .2 .1 .4.5 .5 .5 .5
.4 .4 .5 .5 .4
.5 .5 .4
.3 .4 .4 .4 .4 .4 .4 .4 .4 .4 .4 .4 .4
.4 .2.5 .4
.3 .5
.4 .5 .1 .1 .1 .3
.5 .5 .4
.1 .4
.4 .4.5 .5
.4 .5 .5 .5.1 .5 .2 .1 .4
.5 .5 .5 .5.4 .4 .5 .5 .4.3 .4 .4 .4 .4 .4 .4 .4 .4 .4 .4 .4 .4
Configuration 1 Config. 3
Mfg.Analysisactivitymovedupstream
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-Planning the UAV Development
Process
Plot of RC vs. RS for five process configurations shows trade-off possibilities.
Linear Scale
Cost Risk
1
3
2
45
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Lessons Learned: Cost and Schedule Simulation
Quantify cost and schedule uncertainty and risk
Compare alternative process configurations to reduce risk and choose more robust processes
Visualize simulated process in Gantt chart format
Explore sensitivities toProcess changesLearning curve effectsRework probabilities and impactsActivity costs and durationsControl policies
total duration
Process Robustness
cum
pro
b
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-MIT Design Structure Matrix
Web Site
http://www.DSMweb.org•Tutorial
•Publications
•Examples
•Software
•Contacts
•Events
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- Problematics DSM Software
Download from: http://www.problematics.comIf you would like to use the software for work at your company, you should obtain a separate registration number from Problematics.
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Questions and
Discussion