ESD.36 L3 DSMtaskbaseddspace.mit.edu/.../80702/esd-36j-fall-2003/...task.pdf11 Sep 03 - ESD.36J SPM 21 +-Mathematical Partitioning 12 3 25 145 3 52 25 2 4 2 220 390 10 0 93 70 90 xx

11 Sept 03

ESD.36J System & Project Management

Instructor(s)

+

- Tasked-Based DSMs

Prof. Olivier de Weck

Lecture 3

Based mainly on materials by Prof. Steve Eppinger, © 2003

- ESD.36J SPM11 Sep 03 2

+

- Today’s Topic

DSM IntroductionProject Graphs --> Task-based DSMsDSM Operations

sequencingpartitioningtearing

DSM Tools and References


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- Lessons Learned from CPM/PERT

+Focuses attention on a subset of critical tasksDetermine effect of shortening/lengthening tasksEvaluate costs of a ”crash” programLinks task durations to schedule

-Doesn’t capture task iterations, in fact …Prohibits iterations = called “cycle error”

However, iterations are one of the essentialfeatures of design and development projects


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- PERT and CPM Charts4 2

Start 3

6

Finish

8

5

4

days

activity precedence

critical path

activity and durationSimple network diagrams are easy to understand.We cannot represent the coupled/iterative task relationships.

prohibited


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- Sequencing Tasks in Projects

Three Possible Sequences for Two Tasks

A B

A

B

A

B

Dependent(Series)

Independent(Parallel)

Interdependent(Coupled)

Discussed so far New !


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- Interdependent TasksSometimes iterative tasks are referred to as “chicken-and-egg” problems in designExample from Spacecraft Design

Inertia and Attitude Control Coupling

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+EGGS

CHICKENS

© Lyneis

Define s/csize, massinertia matrix

Size reactionwheel assembly(RWA) torqueand momentumcapacityAdds mass

inertia, ca. 50kg/wheel Reaction

Wheel Assembly

Nexus Spacecraft S/C total mass,total inertia:800kg, 3000 kgm2

External DisturbancesSlew Rate RequirementDesaturation Interval


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- Experiences and QuestionsExamples from your own design experience ?…Questions that arise:

How can iterations be represented?How do you enter the loop?

What are the going-in assumptions?

When do you exit the loop?When has design convergence been achieved?How many iterations are needed?

How do the iterations impact…Project schedule and cost?Product/Design quality?

How can iterations be planned strategically? PDP design = “meta-design”

today

nextlecture


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- What is a DSM?Potential answer to first question:

How can iterations be represented?

Design Structure Matrix (DSM)A two-dimensional matrix representation of the structural or functional interrelationships of objects, tasks or teams

SynonymsDesign Structure Matrix (DSM)N2-Diagram (“N-squared”)Dependency Structure Matrixothers …

Types of DSMsObject-based, Task-based, Team-based


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- Task-Based DSMs

A,0

B,10 D,30

C,20 E,20 F,40

G,20 H,0

Start

Finish

0 10

0 20

20 50

20 40 40 80

80 100

A B C D E F G HABCDEFGH

010

2030

2040

200

task

Project Graph

DSM

inputsinto task

( upstream)

inputsinto task

(downstream)

outputsfrom task( upstream)

translate

outputsfrom task ( downstream)


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- Team-Based DSMs

Team 1

Integration Team

Team 2

Team 4

Team 3

Flywheel Connecting Rods

Crankshaft

Cylinder HeadsIntake Manifold

E.V.A.P. Fuel System Air Cleaner

Throttle Body

Electronic Control Module

PistonsEngine BlockLubrication

Water Pump/Cooling

Camshaft/Valve Train

ExhaustE.G.R.

A.I.R.

Electrical System Ignition Engine Assembly

Accessory Drive

GMEngine

DevelopmentTeam

© Eppinger

F G E D I A C B K J P N Q R B K O L M H S T U VCrankshaft F F • • • • • • • • • • • •

Flywheel G • G • • • •Connecting Rods E • E • • • • • •

Pistons D • • • D • • • • • • • • •Lubrication I • • • • I • • • • • • • • •

Engine Block A • • • • • A • • • • • • • • • •Camshaft/Valve Train C • • • • C • • • • • •

Cylinder Heads B1 • • • • • B1 • • • • • •Intake Manifold K1 • • • • K1 • • • • •

Water Pump/Cooling J • • • • • • J • • • • • • • • •Fuel System P • P • • • • • • • • • •Air Cleaner N • N • • • • • •

Throttle Body Q • • • Q • • • • • • • • •EVAP R • • R • • •

Cylinder Heads B2 • • • B2 • • • • • • • •Intake Manifold K2 • • • • • • K2 • • • • • • •

A.I.R. O • • • • • • O • • • • • •Exhaust L • • • • • • • • L • • • • • •

E.G.R. M • • • • • • • • M • • • • •Accessory Drive H • • • • • • • • • • • • • • • • H • • • •

Ignition S • • • • • • • • • • • • • • • • S • • •E.C.M. T • • • • • • • • • • • • • • • • • • T • •

Electrical System U • • • • • • • • • • • • • • • • • • • U •Engine Assembly V • • • • • • • • • • • • • • • • • • • • • • V

Frequency of PDT Interactions

• Daily • Weekly • Monthly

Team 1

Team 2

Team 3

Team 4

Integration Team

Map IPT teamstructure to DSMvia frequency ofinteraction- daily, weekly, monthly


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-The Design Structure Matrix:An Information Exchange Model

Donald V. Steward, Aug. 1981IEEE Trans. on Eng'g Mgmt.

Interpretation:Task D requires information from tasks E, F, and L.Task B transfers information to tasks C, F, G, J, and K.

Note:Information flows are easier to capture than work flows.Inputs are easier to capture than outputs.

CD

AB

GH

EF

KL

IJ

C DA B G HE F K LI J•

••

••

••

••

••

•


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-

The Design Structure Matrix (Partitioned, or Sequenced)

TaskSequence

Note:Coupled tasks can be identified uniquely. The display of the matrix can be manipulated to emphasize certain features of the process flow.

C

D

A

B

GH

E

F

KL

I

J

C DAB GHEFK L IJ

Sequential

Parallel

Coupled

••

••

••

••

••

••


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- Tearing Marks in the DSM

C

D

A

B

GH

E

F

KL

I

J

C DAB GHEFK L IJ

Series

Parallel

Coupled

••

••

••

••

••

••

Tear This Mark C

D

A

B

GH

E

F

KL

I

J

C DAB GHEFK L IJ

Series

Parallel

Coupled

••

••

••

••

••

••

Control

Tear the marks which break the coupled block into smaller ones or make it sequential.

Torn marks may becomeAssumptionsFeedbacksControls for the process


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- DSM Sequencing ExerciseA B C D E F G H I J

A A X X X AB X B X X X BC C CD D X X X DE X E X EF X X X X F X FG X G X GH X X H X HI X X X I IJ X X J J

A B C D E F G H I JExcelMacro


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-

Concurrent Engineering in the Small

Projects are executed by a cross-disciplinary team (5 to 20 people).Teams feature high-bandwidth technical communication.Tradeoffs are resolved by mutual understanding.“Design and production” issues are considered simultaneously.


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Concurrent Engineering in the Large

Large projects are organized as a network of teams (100 to 1000 people).Large projects are decomposed into many smaller projects.Large projects may involve development activities dispersed over multiple sites.The essential challenge is to integrate the separate pieces into a system solution.The needs for integration depend upon the technical interactions among the sub-problems.


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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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-How to Create a Task-Based Design Structure Matrix Model

Select a process or sub-process to model.Identify the tasks of the process, who is responsible for each one, and the outputs created by each task.Lay out the square matrix with the tasks in the order they are nominally executed.Ask the process experts what inputs are used for each task.Insert marks representing the information inputs to each task.Optional: Analyze the DSM model by re-sequencing the tasks to suggest a new process.Draw solid boxes around the coupled tasks representing the planned iterations.Draw dashed boxes around groups of parallel (uncoupled) tasks.Highlight the unplanned iterations.


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-Mathematical Partitioning

1 2 3

2 5

1 4 5 3

5 2

2 5 2 4 2

2 2 03 9 0

10 09 3 7 0

9 0

x x xx xx x x xx xx x x x x

− + =

+ − =− − + =− + =

− + − =

E1

E2

E3

E4

E5

-5 variables-5 independent equations-no degrees of freedom

Occurrence Matrix Irreducible Subsets

1. Solve x2,x5 from E2 and E42. Solve x4 from E53. Solve x1 and x3 from E3 and E1


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- Problematics DSM Software

Download the latest version of the PSM32 program at:

http://www.problematics.com30 day free trial version40 tasks maximum

http://www.problematics.com/


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- Brake-System Design Process


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- PSM32 Functionality

PartitioningDetect sequential, parallel and iterative task (blocks)

Ordering/SequencingTearing

Analyze block structureBreak big blocks into smaller blocks - torn mark becomes an assumption in the design processDetermine number of iterations to converge

SchedulingDevelop schedule and critical path (given task durations)

PSM32= “DSM Analyzer and Manipulator”


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- PSM32 Toolbar : Summary

Exit

Create new project

Open a project

Print Insert a row Zoom (percentage)

Move down diagonally

Help

Info/Options Delete a row Zoom in Reset Matrix

Find Move row down

Mark notes Move up diagonally Tear

Save Move row up

Edit row Zoom out Partition


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- Partitioning


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- Identifying the Mark to Tear

Tear (assume) this information


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-

Separation of Kinematics from Thermodynamics

Kinematics (Stopping the Car)

Thermodynamics (Cooling the Brakes)


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- What’ really different?“In a critical path schedule this simultaneous or iterative situation does not arise or is not explicitly shown because one is dealing only with items to be done. But here we are dealing both with what is to be done and what information is to be determined. Information is needed to determine how a task item it to be done, and information is produced by doing the task. The introduction of information flowraises the possibility, indeed the probability, of being confronted with blocks of more than one item where each item in the block depends on all the other items in the same block. This is usually resolved by making assumptions and iterating to refine the assumptions.”

D. Steward


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- ConclusionsIterations are an essential part of design

Some iterations are desirableimprove quality

Some iterations are undesirable (rework)can cause delay and cost increases

Differences between CPM/PERT and DSMCPM/PERT is work-flow oriented

time and schedule flowuseful for planning and tracking detailed execution of project

DSM is information-flow orientedDSM captures iterationsDSM shows blocks , i.e. the macro-tasksuseful for analyzing and improving design processes

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Documents

ESD.36 L3 DSMtaskbaseddspace.mit.edu/.../80702/esd-36j-fall-2003/...task.pdf11 Sep 03 - ESD.36J SPM 21 +-Mathematical Partitioning 12 3 25 145 3 52 25 2 4 2 220 390 10 0 93 70 90 xx