University:
Massachusetts Institute of Technology
Course:
15.501/516 | Accounting
Academic year:

2023
Views:

189

Pages:

33
Author:

Rimbaudevjdp

Tools For Innovation: The Design Structure Matrix Outline Overview Design Structure Matrix (DSM) Basics How to create Classification The Iteration Problem: Traditional Project Management Tools and Product Development Increasing Development Speed Sequencing, Partitioning and Simulation The Integration Problem: DSM Clustering Organizational Structures & Product Architectures Classical Project Management Tools Gantt Charts Graph-based: PERT, CPM, IDEF Activity Time Characteristics Complex Depiction Focus on Work Flows Ignore Iterations & Rework DSM focuses on Information Flows Test results, Planned design reviews, Design mistakes, Coupled nature of the process Decomposition & Integration Assume optimal Decomposition & Structure Integration of Tasks not addressed Design Iteration Iteration: The repetition of tasks due to new information. Fundamental in Product development Changes in input information (upstream) Update of shared assumptions (concurrent) Discovery of errors (downstream) Often times hidden Understanding Iterations requires Visibility of information flows Decomposition and Integration Decomposition: Dividing a complex problem into smaller sub-problems. Integration: Combining sub-problems to achieve set goals. A Graph and its DSM B A C D E F G H I A B C D E F G H I A A B B X C X D E F G H I X C D X E X X F X X G H X I Creating a DSM Design manuals Process sheets Structured expert interviews Interview engineers and managers Determine list of tasks or parameters Ask about inputs, outputs, strengths of interaction, etc Enter marks in matrix Check with engineers and managers Questionnaires Four Types of DSMs Iteration Activity based DSM Parameter based DSM Sequencing Partitioning Simulation Integration Team based DSM Product Architecture DSM Clustering Iteration Focused Tools Concepts, Examples, Solution Approaches Sequencing Tasks in Projects Possible Relationships between Tasks A A A B B Independent (Parallel) Interdependent (Coupled) B Dependent (Series) Sequencing Algorithm Step 1: Schedule tasks with empty rows first Step 2: Delete the row and column for that task Step 3: Repeat (Go to step 1) Step 4: Schedule tasks with empty columns last Step 5: Delete the row and column for that task Step 6: Repeat (Go to step 4) Step 7: All the tasks that are left unscheduled are coupled. Group them into blocks around the diagonal Project Scope Activity Activity Questionnaire M S M M W W Organized Activity Diagram M S W Verify Verify A-A & A-I A-A & A-I Matrices Matrices Information Activity Activity Gate Reviews I I I I I I I I Verify Verify OAOADiagram Diagram I I Consult Consult Key Functions Key Functions and and Clients Clients Stage Overlapping .. . Consult Consult Key Functions Key Functions and and Executives Executives Final Process Structure Time Cost Trade-Offs I II III IV Sensitivity Sensitivity Analysis Analysis Opportunity Opportunity Costs Costs Corresponding Literature Structuring StructuringProduct ProductDevelopment DevelopmentProcesses Processes Ahmadi, Roemer & Wang, Ahmadi, Roemer & Wang, European EuropeanJ.J.of ofOperational Operational Research Research2001 2001 Managing ManagingDevelopment DevelopmentRisk Riskin inProduct Product Design DesignProcesses Processes Ahmadi Ahmadi&&Wang, Wang,Oper. Oper.Res. Res.1999 1999` ` Time-Cost Time-CostTrade-Offs Trade-Offsin inOverlapped OverlappedProduct Product Development Processes Development Processes Roemer, Roemer,Ahmadi Ahmadi&&Wang, Wang,Oper. Oper.Res. Res. 2000 2000 Accelerating AcceleratingProduct ProductDevelopment Development Roemer & Ahmadi, In Roemer & Ahmadi, Inreview reviewat atOper. Oper.Res. Res. ... Finding Coupled Stages Block Creation Block Decomposition Design Time Computation Block Decomposition min ∑ aij nij yij ij∈A M ∑x s.t. m =1 im = 1, ∀ i N ∑ xim ≤ C , ∀ m i =1 xim − M ∑x h = m +1 jh − yij ≤ 0, ∀ i, j , m xim , yij ∈ {0,1}, ∀ i, j , m i,j = index for activities, i,j = 1,2,…,N; m = index for stages, m = 1,2,…,M; A = the set of directed arcs in the design graph; aij = the level of dependency of activity i on j ⎧1 if activity i is assigned to stage m xim = ⎨ ⎩0 otherwise ⎧0 if arc ij is a feed back between stages yij = ⎨ ⎩1 otherwise ⎧W nij = ⎨ ⎩1 (a large number) if aij = 1 otherwise Lead Time Estimation Exp. Iterations µ ji = (I − P )−1 Markov Chain Activity Duration Ti = ti + e −1 / β i ∑ [t + (t µ1i −1 n =1 0 i i Stage Duration T = ∑i =1 Ti k ) −t e 0 i − λi n .3 ] .5 1 1 1 .2 2 3 .5 .5 S T Decomposition and Duration Block Duration 100% 80% 60% 40% 20% 0% 0 5 10 15 20 25 Decomposition Degree (Number of Process Stages) 30 Duration Increase 1000% 35 30 Number of Iterations Duration 800% 25 600% 20 400% 15 10 200% 0% 5 1 2 3 4 5 6 7 8 Number of Activities 9 10 11 0 Number of Iterations Stage Size and Duration X Task A DSM Simulation Task C X X Task A requires input from task C Perform A by assuming a value for C’s output Deliver A’s output to B Deliver B’s output to C Feed C’s output back to A Task B Check initial assumption (made by A) Update assumption and repeat task A. Simulating Rework R Task A Task B Task C X X R is the probability that Task A will be repeated once task C has finished its work. R = 0.0 : There is 0 chance that A will be repeated based on results of task C. R = 1.0 : There is 100% probability that A will be repeated based on results of task C. Simulating 2nd Order Rework X Task A Task B Task C R2 X Second Order rework is the rework associated with forward information flows that is triggered by feedback marks. First order rework: Output of task C causes task A to do some rework 2nd order rework: Consequently there is a chance tasks depending on A (e.g. task B) will also be repeated. Simulating Rework Impact I Task A Task B Task C X X I = 0.0 : If task A is reworked due to task C results, then 0% of task A’s initial duration will be repeated I = 1.0 : If task A is reworked due to task C results, then 100% of task A’s initial duration will be repeated Simulation Results DSM contains rework probabilities and impacts Cost and time add up Many runs produce a distribution of total time and cost Different task sequences can be tried Gantt Chart with Iteration Typical Gantt chart shows monotone progress Actual project behavior includes tasks stopping, restarting, repeating and impacting other tasks Lessons Learned: Iteration Development is inherently iterative. Understanding of coupling is essential. Iterations improve quality but consumes time Iteration can be accelerated through: Information technology (faster iterations) Coordination techniques (faster iterations) Decreased coupling (fewer iterations) Two Types of Iteration: Planned Iterations (getting it right the first time) Unplanned iterations (fixing it when it’s not right) Integration Focused Tools Concepts, Examples, Solution Approaches Team Selection Team assignment is often opportunistic “We just grab whoever is available.” Not easy to tell who should be on a team Tradition groups people by function Info flow suggests different groupings Info gathered by asking people to record their interaction frequency with others Clustering a DSM A B C D E F G A A B B C C D D E E F F G G No Dependency Low A F E D B C G A A F F E E D D B B C C G G Hi Alternative Arrangement Overlapped Teams A F E D B C G A A F F E E D D B B C C G G No Dependency Low A F E D B C G A A F F E E D D B B C C G G Hi GM’s Powertrain Division 22 Development Teams into four System Teams Short block: block, crankshaft, pistons, conn. rods, flywheel, lubrication Valve train: cylinder head, camshaft and valve mechanism, water pump and cooling Induction: intake manifold, accessory drive, air cleaner, throttle body, fuel system Emissions & electrical: Exhaust, EGR, EVAP, electrical system, electronics, ignition Lessons Learned: Integration Large development efforts require multiple activities to be performed in parallel. The many subsystems must be integrated to achieve an overall system solution. Mapping the information dependence reveals an underlying structure for system engineering. Organizations and architectures can be designed based upon this structure. Conclusions The DSM supports a major need in product development: documenting information that is exchanged It provides visually powerful means for designing, upgrading, and communicating product development activities It has been used in industry successfully