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Decomposition: Architecture &Trade Studies

Mark E. Sampson

UPDATED 9/20/04

EMIS 8390

Systems Engineering Tool—applying tools to engineering systems

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Architectural Frameworks…

• …a means of representing, capturing, communicating system architectures from a variety of perspectives…

• 100’s of frameworks out there…• Aimed at different problem domains

Business/IS systems…Zachman, SEMS, EPIC,…

Tools help capture & support these frameworks…CaseWise, Synthesis,…

Usually can’t buy them without consulting

Business consultants each have their own extensions/tools

[zifa.com]

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Architectural Frameworks…continued

• IDEF0-9…based on SADT

• IDEF0—functional modeling…• IDEF1—information modeling…• IDEF1x—activity modeling…• IDEF2—system dynamics• IDEF3—process & states• IDEF4—object modeling• …• IDEF9—user interface • …• IDEF14—network modeling

Tools help capture & support these frameworks…KBSI, Popkin SA, ProSim,…

[idef.com]

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Architectural Frameworks…continued

• DoDAF…next generation C4ISR

• Operational views• OV1-operational concepts• …• OV5-activities• …• OV9-logical Data

• System views • SV1-interfaces• …• SV12-events

Tools help capture & support these frameworks…Popkin SA, Statemate, P-Tech…

Most used is Powerpoint, Excel,…

J-STARSw ATR

U-2

CAOC

UAV

DCGS

AEGIS

USMCTAOC

AIR DEFENSETOC

TADITADIL L

NETNET

TADITADIL L

NETNET

BCC

ARMY TacticalOperations Center

XX

XX

XXX

XX

TCT Kill Chain TCT Kill Chain Engaged by a Joint Battle ForceEngaged by a Joint Battle Force

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Architecture: Synthesis…

• Translates functions into physical architecture by grouping functions into logical/physical elements

• Elements include: hardware, software, material, data, facilities, people, services, and/or processes

• Alternatives are evaluated against the requirements to identify best approach

• Continue to develop architecture until you can verify that requirements have been met

…produces WBS, spec’s, & CI’s[SE Handbook 10] [DOE 2003]

Battery

Processor

Motor

Drive

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Architecture: Synthesis…

• You “just” have to choose an architecture that:

1. Satisfies the requirements2. Implements the functions3. Within budget, time, knowledge, resources,…4. Built with available technology & availability risk5. Is extensible to accommodate growth & new

technologies6. Allows you to go the next level of detail7. Is robust enough to minimize back-tracking

…you may be starting from scratch or from existing art…in a changing environment

[SE Handbook 10]

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Architecture: Synthesis…

1. Develop alternatives use the tools previously described—brainstorming, morphing, surveys, literature search, Pugh, TRIZ,…

2. Develop architectures from those alternativesuse diagrams/models of appropriate types (at appropriate level)

3. Choose & dive to the next levelapply criteria, decision trees, weighting, utility curves…

• Repeat until components arerealizable, verifiable…

[SE Handbook 10]

Problem Definition

FunctionalAnalysis

Systems Synthesis

Systems Analysis

DecompositionVerificationValidation

Develop Alternatives

Develop ArchitectureChoose

Alternative

Develop ArchitectureChoose

Alternative

Develop Alternatives

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Modeling Methodology: Schematic Block Diagrams

…capture & communicate potential product architecture, what makes it up, & their interactions

• Shows internal & external interfaces without pushing a particular design• Encourages looking “outside the box”

In our dental hygiene case, shows the preliminary product partitioning

[Armstrong 1993]

Partitioning

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Modeling Methodology: Behavior Diagrams

…combine data flow and functional flow

• More thorough analysis of actions & what is being acted on in the same diagram. • Support function to system allocations

…tools like CORE, Cradle-SEE,…use thesetypes of diagrams

[Armstrong 1993]

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Modeling Methodology: State Diagrams

…analysis of system states or modes

• Identify lock conflicts—on, standby,…• Identify transition problems during design

Presentation/Demo by I-logix

In our dental hygiene case, shows the system needs to be made ready before it can be used

[Armstrong 1993]

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Modeling Methodology: Object Oriented Analysis

…identify what the system will have to deal with as objects

• Similar to mission profiles, schematic block diagrams,…

•UML/SysML…Presentation by Sandy Friedenthal (LMCO/SySML Partners)

In our dental hygiene case, shows objects of our dental monitoring system

[Armstrong 1993]

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Modeling Methodology: Data Flow

…like functional flow, except emphasis on how information flows among system elements.

Helps identify data input/outputconflicts• Data dictionaries

In our dental hygiene case, shows a decomposition of monitoring brushing after meals

[Armstrong 1993]

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Modeling Methodology: others…

• Entity-Relationship Diagrams• Math models (Excel, Matlab,…)• Statistical Models—DFSS,…(SAS, MiniTab,…)• Performance models—Queuing, Monte Carlo, etc.

(Crystal Ball, SES Workbench,…)• Environmental Models—• Physical Models—Hydraulics, Electrical,…(Easy5,

CAERose, Matlab:Simulink…)

[Armstrong 1993]

Product ModelProduct Model(equation, (equation, simulation,simulation,

workbook, data,workbook, data,hardware, etc.)hardware, etc.)

C

E

A

B

D “Non-compliant”

“Non-compliant”

Y

ULLL T

PNCPNC

“Compliant”

Product ModelProduct Model(equation, (equation, simulation,simulation,

workbook, data,workbook, data,hardware, etc.)hardware, etc.)

C

E

A

B

D “Non-compliant”

“Non-compliant”

Y

ULLL T

PNCPNC

“Compliant”

Product Requirement I

Customer Need

Module A Requirement Module B Requirement Module C Requirement

Assembly 1Requirement

Assembly 2Requirement

Assembly 1Requirement

Assembly 2Requirement

Assembly 1Requirement

Assembly 2Requirement

Component 1Requirement

Component 2Requirement

Component 3Requirement

Process 1Requirement

Process 2Requirement

CustomerEnvironment

ProductDevelopment Team

Environment

Product Requirement I

Customer Need

Module A Requirement Module B Requirement Module C Requirement

Assembly 1Requirement

Assembly 2Requirement

Assembly 1Requirement

Assembly 2Requirement

Assembly 1Requirement

Assembly 2Requirement

Component 1Requirement

Component 2Requirement

Component 3Requirement

Process 1Requirement

Process 2Requirement

CustomerEnvironment

ProductDevelopment Team

Environment