Design Structure Matrix: Iteration Models

Transcription

1 ESD.36J System & Project Management Lecture 4 Design Structure Matrix: Iteration Models Instructor(s) Prof. Steven D. Eppinger 2003 Steven D. Eppinger 9/16/2003

2 Today s Topics Iteration Models Planned vs. Unplanned Sequential vs. Parallel Product Development Process Analysis using DSM Industrial Examples Comparing alternative processes Process Improvement using DSM Design Modes Work Transformation Model Cost and Schedule Simulation Introduce HW2 9/16/03 ESD.36J SPM 2

3 Semiconductor Development Example Set customer target x x 2 Estimate sales volumes x x x 3 Establish pricing direction x x 4 Schedule project timeline Concurrent Activity Blocks x 5 Development methods x x x x x Generational Learning 6 Macro targets/constraints x x x x x x 7 Financial analysis x x x x x 8 Develop program map x x 9 Create initial QFD matrix x x x x Potential Iterations x 11 Write customer specification x x x x x O O O O 10 Set technical requirements x x x x O O O O 12 Highlevel modeling x x x x x x x 13 Write target specification x x x x x x x x x x x 14 Develop test plan x x x x x x 15 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 O 18 Develop product modules x x x x x x x x x O 19 Lay out integration x x x x x x x x x 20 Integration modeling x x x x x x x x x x 21 Random testing x x x x x 22 Develop test parameters x x x x x x x x x x 23 Finalize schematics x x x x x x x O O O O O 24 Validation simulation x x x x x x x x x 25 Reliability modeling x x x x x x 26 Complete product layout x x x x x x x 27 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 O 30 Generate masks x x x x x O 31 Verify masks in fab x x x 32 Run wafers x x O 33 Sort wafers x 34 Create test programs x 35 Debug products x x x x x O O O O O O O 36 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 Sequential Activities 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 x 45 Develop service courses x x x 46 Determine marketing name x x x x x x 47 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 x 51 Infant mortality testing x x x x x 52 Mfg. process stabilization x x x O O 53 Develop field support plan x x 54 Thermal testing x x x 55 Confirm process standards x x x 56 Confirm package standards x x x x x x 57 Final certification x x x x x x x x x x x 58 Volume production x x x x 59 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 9/16/03 ESD.36J SPM 3

4 Two Types of Iteration Planned Iteration Caused 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 Iteration Caused by errors and/or unforeseen problems. We generally cannot predict which unplanned iterations will occur. Unplanned iterations should be minimized using risk management methods. 9/16/03 ESD.36J SPM 4

5 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 flows understanding of the inherent process coupling 9/16/03 ESD.36J SPM 5

6 Instrument Cluster Development Delco Supplier Casing Design X X Casing Design X Wiring 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 Slower Design Process Several planned iterations Usually one unplanned iteration Faster Design Process Fewer planned iterations Planned revision cycle No unplanned iterations 9/16/03 ESD.36J SPM 6

7 Two Iteration Styles Sequential Iteration One activity is executed at a time. Models assume that probabilities determine the next actions. Signal Flow Graph Model Parallel Iteration Several activities are executed at a time. Models assume that rework is created for other coupled activities. Work Transformation Model A B C A B C 9/16/03 ESD.36J SPM 7

8 Stamping Die Development Process Panel Design Panel Data Die Design Die Geometry Manufacturability Evaluation Analysis Results Die Geometry Analysis Results Surface Data Surface Data Surface Modeling Verification Data Prototype Die Verification Data Surface Data Production Die 9/16/03 ESD.36J SPM 8

9 Signal Flow Graph Model: Stamping Die Development Die Prelim. Mfg. Die Prelim. Mfg z 2 1 z z 1 Die Start z 3 Design1 z 3 Eval.1 Design2 Eval.2 Design z z z2 pz t duration probability Init. Surf. Modeling 0.9 z 3 Final Surf. Modeling z1 z 0. 5 z Final Mfg. Eval. 1 Finish 9/16/03 ESD.36J SPM 9

10 Computed Distribution of Die Development Timing probability time (days) 9/16/03 ESD.36J SPM 10

11 Comparing Alternative PD Processes C Design 1 B+C Eval+Test Process A No CFD analysis Process B Use CFD in evaluation Process C Use CFD in design + eval. C Design 2 B+C Eval+Test Proceed Rework (to be avoided) Evaluation of Design Process Alternatives using Signal Flow Graphs O. Isaksson, S. KeskiSeppälä, S.D. Eppinger Journal of Engineering Design, Sept Application: Jet Engine Development Volvo Aero Corp. 9/16/03 ESD.36J SPM 11

12 Probability of Completion Comparing Alternative PD Processes Process A No CFD analysis Process B Use CFD in evaluation Process C Use CFD in design + eval E[LT] C E[LT] B E[LT] A Completion Time (days) 9/16/03 ESD.36J SPM 12

13 Brake System Design Example 105 parameters ** ** ** ** X ** X ** XX ** X ** X ** X ** X X ** X X X ** X X ** X X ** XX X X ** ** X X ** X X X ** XX X ** X XX 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 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 XXX XX X **X X X X X XXX XX X **X X X X X XXX XX X ** X X X XX X X X ** X X XX XX 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 XXX XX X XXX ** 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 ** XXX X ** X X X**X X X X X X X X X X X **XX ** X XXX X X X X X X X X ** X X X X X X X **X X X XX X XX**XX X XX X X XX XX XX XX X**X X XX XXX XX X XX XX**XX X X X X X ** X X X X X XX** X X ** XX X X X ** X X XX X XXX** X X XX X XXXX** X X X XX X X X ** X** X X XX X XX**X X X X X X X** X X ** XX ** X X ** X XX X X ** X XXX 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 X X X X X X ** X X X X X X ** X X X X X ** X X X ** XXX X X X X ** X X X X X ** XX ** X XXX XX X X X X ** X XXX XX X X X X X ** X XXX XX X X X X ** XX X XXX X XX ** XX XX X X X X X X X ** ** X X X X X ** X ** X XXX X XXX 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 ** 9/16/03 ESD.36J SPM 13

14 Brake System Coupled Block Knuckle envelope & attach pts ** 34 Pressure at rear wheel lock up ** x X 35 Brake torque vs. skidpoint ** x x x x 37 Line pressure vs. brake torque ** x 40 Splash shield geometry front ** x x x 44 Drum envelope & attach pts ** 45 Bearing envelope & attach pts ** 46 Splash shield geometry rear ** 48 Air flow under car/wheel space x x ** x 49 Wheel material ** x 50 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 x 55 Lining rear vol and area x ** x 56 Rotor width x x ** x x 57 Pedal attach pts ** x 58 Dash deflection x ** x 59 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 x 64 Booster reaction ratio x x ** 65 Rotor diameter ** x 66 Rotor envelope & attach pts x ** 104 Rotor material x ** Weak x Medium X Strong 9/16/03 ESD.36J SPM 14

15 The Work Transformation Model (Parallel Iteration Model) u t +1 = Au t work vector Assumptions work transformation matrix All coupled tasks are attempted simultaneously. Offdiagonal 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. 9/16/03 ESD.36J SPM 15

16 Work Transformation Model Mathematics U = t =0 u t +1 = Au t u t = ( A t )u 0 U=S Λ t t=0 t =0 A = SΛS 1 t=0 Λ t S 1 u 0 = (I Λ) 1 [ ] U = S(I Λ) 1 S 1 u 0 work transformation equation total work vector eigenvalue decomposition substitution diagonal matrix of 1 1 λ Total work is a scaling of the eigenvectors. terms total work eigenvector matrix scaling vector 9/16/03 ESD.36J SPM 16

17 Brake System Design Modes slower Rate of Convergence faster Design Mode 9/16/03 ESD.36J SPM 17

18 Brake System Design Modes First Second Knuckle envelope & attach pts Pressure at rear wheel lock up Brake torque vs. skidpoint Line pressure vs. brake torque Splash shield geometry front Drum envelope & attach pts Bearing envelope & attach pts Splash shield geometry rear Air flow under car/wheel space Wheel material Wheel design Tire type/material Vehicle deceleration rate Temperature at components Rotor cooling coefficient Lining rear vol and area Rotor width Pedal attach pts Dash deflection Pedal force (required) Lining material rear Pedal mechanical advantage Lining front vol & swept area Lining material front Booster reaction ratio Rotor diameter Rotor envelope & attach pts Rotor material Stopping Performance Design Mode Thermal Design Mode 9/16/03 ESD.36J SPM 18

19 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 /16/03 ESD.36J SPM 19

20 Turbine Blade Development DSM Existing Process: Different CAD Tools Proposed Process: Common CAD Tools 9/16/03 ESD.36J SPM 20

21 DSM (WTM) Analysis Results 9/16/03 ESD.36J SPM 21

22 Lessons Learned: Iteration Development 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. 9/16/03 ESD.36J SPM 22

23 DSM Simulation Quantifies Cost and Schedule Risk Taskbased project network model using DSM representation Effects modeled: Probabilistic iteration and rework Learning effects Stochastic task durations and costs Resource constraints Overlapping tasks Riskbased control of parallel rework Discreteevent MonteCarlo simulation Latin Hyper Cube sampling Simulation 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 912, Modeling Impacts on Cost and Schedule Risks in Product Development, Tyson R. Browning and Steven D. Eppinger, Working Paper /16/03 ESD.36J SPM 23

24 UAV Concept Study DSM Inputs Unmanned Aerial Vehicle Preliminary Design Activities Exp. Duration Tasks, Durations, Learning Parameters Lear ID Task Name Opt. Likely Pess. ning 1 Prepare UAV Preliminary DR&O Create UAV Preliminary Design Confinguration Prepare Surfaced Models & Internal Drawings Perform Aerodynamics Analyses & Evaluation Create Initial Structural Geometry Prepare Structural Geometry & Notes for FEM Develop Structural Design Conditions Perform Weights & Intertias Analyses Perform S&C Analyses & Evaluation Develop Freebody Diagrams & Applied Loads Establish Internal Load Distributions Evaluate Structural Strength, Stiffness, & Life Preliminary Manufacturing Planning & Analyses Prepare UAV Proposal ID Precedence, Rework Probability, Impact MIT Lean Aerospace Initiative 9/16/03 ESD.36J SPM 24

25 Simulated Schedule of UAV Preliminary Design Process (1 of 1000 simulation runs) ID \ State D (w /o rew ork) D (w. rew ork) /16/03 ESD.36J SPM 25

26 Results for UAV Preliminary Design Process Target COST: P C (un.) 24% Cost ($k) Target SCHEDULE: P S (un.) 91% Schedule (days) 9/16/03 ESD.36J SPM

27 Joint PDF of Paired [C, S] Samples Schedule (days) Cost ($k) Insight: Bimodal PDF has similar cost but different schedule outcomes. 9/16/03 ESD.36J SPM 27

28 Contour Plot View of Joint [C, S] PDF Budget target Schedule (days) Schedule target Cost ($k) 9/16/03 ESD.36J SPM 28

29 Comparing Alternative UAV Development Processes Configuration 1 Config Mfg. Analysis activity moved upstream /16/03 ESD.36J SPM 29

30 Planning the UAV Development Linear Scale Process Cost Risk Plot of R C vs. R S for five process configurations shows tradeoff possibilities. 9/16/03 ESD.36J SPM 30

31 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 to Process changes Learning curve effects Rework probabilities and impacts Activity costs and durations Control policies cum prob Process Robustness total duration 9/16/03 ESD.36J SPM 31

32 MIT Design Structure Matrix Web Site Tutorial Publications Examples Software Contacts Events 9/16/03 ESD.36J SPM 32

33 Problematics DSM Software Download from: If you would like to use the software for work at your company, you should obtain a separate registration number from Problematics. 9/16/03 ESD.36J SPM 33

34 Questions and Discussion 9/16/03 ESD.36J SPM 34