principles of engineering system design

Principles of Principles of

Engineering System DesignEngineering System Design

Dr T Asokan

[email protected]

http://www.guarniero.nl/Rockets/Ariane5/images/Ariane5.htm

INTRODUCTION TO SYSTEMS DESIGN

Dr T [email protected]

Physical Architecture Development

Six functions of Design Process

1. Define System Level Design Problem

2. Develop the system functional architecture

3. Develop the system physical architecture

4. Develop the system operational architecture

5. Develop the interface architecture

6. Define the qualification system for the system

Case Study: Aircraft crash- Iowa

United 232: 3-engine aircraft crashed on 19/7/1989 while making an emergency landing after losing one of the three engines. 110 people died, 185 survived.

The fan disk of the engine at the fuselage separated from the engine and crashed through the tail.

Two engines were quite sufficient to make a safe landing, but the aircraft stabilization system failed to control the descent rate.

Three redundant hydraulic systems, each powered by a unique engine, were available for aircraft stabilisation.

The three hydraulic system converged at the location near the tail where the fan disk ripped out, the single point of failure for all the hydraulic systems.

A pre-existing fracture on the surface of the fan disk was identified as the main cause of engine failure

The design flaw of single point failure resulted in the aircraft crash.

Physical ArchitecturePhysical architecture of a system is a hierarchical description of the resources that comprise the system.

The hierarchy begins with the system and the system’s top-level components and progresses down to the configuration items (CI).

The CIs could be software, hardware, or a combination of hardware and software, people, facilities, documents etc.

It provides resources for every function identified in the functional architecture

Physical Architecture Development Generate a generic physical architecture from

functional architecture

Create a morphological box for alternative physical elements

Generate alternative instantiated architectures

Select suitable physical architecture

The exit criterion is the provision of a single physical architecture that is satisfactory in terms of detail, quantity, and quality for development

GenericPhysiclaArchitecture

Generate aMorphological Box

for AlternateInstantiated Phisical

ArchitectureA1132

A1133

A1131

SelectAlternate

InstantiatedPhysical

Architecture

Brainstorms andSelect a Generic

PhysicalArchitecture

System-levelOperationalConcept

PhysicalArchitectureChanges

System-levelFunctional

Architecture

Originating & SystemRequirements,

Objectives Hierarchy,Boundary & Qualification

System Requirements

CandidateGeneric

PhysicalArchitectures

MorphologicalBox

System-levelPhysical

Architecture

CandidatePhysical

Architectures

T Asokan ED309

GenericPhysiclaArchitecture

Generate aMorphological Box

for AlternateInstantiated Phisical

ArchitectureA1132

A1133

A1131

SelectAlternate

InstantiatedPhysical

Architecture

Brainstorms andSelect a Generic

PhysicalArchitecture

System-levelOperationalConcept

PhysicalArchitectureChanges

System-levelFunctional

Architecture

Originating & SystemRequirements,

Objectives Hierarchy,Boundary & Qualification

System Requirements

CandidateGeneric

PhysicalArchitectures

MorphologicalBox

System-levelPhysical

Architecture

CandidatePhysical

Architectures

T Asokan ED309

Generic Physical Architecture is a description of the partitioned elements of the physical architecture without any specification of the performance characteristics of the physical resources that comprise each element.

It provides common designators for physical resources in a hierarchical decomposition.

No specific physical items are identified here.

GENERIC ARCHITECTURE

Func.1.1.1

Func.1.1.2

Func.1.1.3

Func.1.2.1

Func.1.2.2

Func.1.3.3

Func. 2.1 Func. 2.1

more level 1 functions

more level 2 func.

Lower level functions

Shows the function and hierarchy

SYSTEMFUNCTION

Function1 Function2

Func 1.1 Funct 1.2 Funct 1.3

T Asokan ED309

Func.1.1.1

Func.1.1.2

Func.1.1.3

Func.1.2.1

Func.1.2.2

Func.1.3.3

Func. 2.1 Func. 2.1


more level 2 func.

Lower level functions


SYSTEMFUNCTION

Function1 Function2

Func 1.1 Funct 1.2 Funct 1.3

.

Accept passenger requests, provide feedback

Move passengers between floors

Control elevator cars



Provide I/Ointerface Process data Provide control

commandsFunc. 2.1 Func. 2.1

Func.1.1.1 Func.1.1.2 Func.1.1.3

Func.1.2.1 Func.1.2.2 Func.1.2.3


T Asokan ED309

.






Provide I/Ointerface Process data

Provide controlcommands

Func. 2.1 Func. 2.1

Func.1.1.1 Func.1.1.2 Func.1.1.3

Func.1.2.1 Func.1.2.2 Func.1.2.3


Elevator System

PassengerInterface

Component

CarComponent

Car ControlComponent

ElevatorCar/Shaft

Component

Shaft StructuralComponent

HardwareComponent

SoftwareComponent

Shaft SwitchComponent

Floor StopComponent

LevelingComponent

Drive/BrakeComponent

Exit Component& Controls

Elevator CallAnnouncement

Component

DestinationControl

Component

DoorControl

Component

EmergencyComponent

PhoneComponent

Ventilation& Lighting

Component

Interior DoorComponent

CabComponent

ControlComponnet

Maintenance& Self - TestComponent

NormalDrive/BrakeComponent

EmergencyBraking

ComponentT Asokan ED309

.






Provide I/Ointerface Process data Provide control

commandsFunc. 2.1 Func. 2.1

Func.1.1.1 Func.1.1.2 Func.1.1.3

Func.1.2.1 Func.1.2.2 Func.1.2.3


T Asokan ED309

Elevator System

PassengerInterface

Component

CarComponent


ElevatorCar/Shaft

Component


HardwareComponent

SoftwareComponent


Floor StopComponent

LevelingComponent




Component

DestinationControl

Component

DoorControl

Component

EmergencyComponent

PhoneComponent


Component


CabComponent

ControlComponnet



EmergencyBraking

Component

AircraftDevice

Sensors

CrewCommand

Devices(e.g.,

throttle,pedals?

CrewCommandSensors

CentralController

ActuatorController Actuator


AircraftDevices

(e.g.,flaps,

ailerons)

Aircraft Control ComponentT Asokan ED309

T Asokan ED309

AircraftDevice

Sensors

CrewCommand

Devices(e.g.,

throttle,pedals?

CrewCommandSensors

CentralController



AircraftDevices

(e.g.,flaps,

ailerons)

Aircraft Control Component

Instantiated Physical Architecture is a generic physical architecture to which complete definitions of the performance characteristics of the physical resources have been added.

Functions Functions ComponentsComponents

ff

f

f

ff

ff

f

f

cc

cc

c

cc

cc

c

1 1 112 22 2

3 3 334444

5 555

One- to- one and ontofunction for the allocation

of functions to components

Function for the allocationof functions to components

T Asokan ED309

Functions Functions ComponentsComponents

ff

f

f

ff

ff

f

f

cc

cc

c

cc

cc

c

1 1 112 22 2

3 3 334444

5 555

One- to- one and ontofunction for the allocation

of functions to components

Function for the allocationof functions to components

Elevator System

PassengerInterface

Component

CarComponent


ElevatorCar/Shaft

Component


HardwareComponent

SoftwareComponent


Floor StopComponent

LevelingComponent




Component

DestinationControl

Component

DoorControl

Component

EmergencyComponent

PhoneComponent


Component


CabComponent

ControlComponnet



EmergencyBraking

Component Instantiated ArchitectureT Asokan ED309

MAPPING

Morphological Box for alternatives

A morphological box is a matrix representing the components of the generic architecture and the alternative choices for fulfilling that generic component.

Morphological analysis divides a problem into segments and posits several solutions for segment.

T Asokan ED309

Morphological box for a hammer

HandleSize Handle Material Striking Element

Weight ofHammer Head

Nail RemovalElement

8 inches

22 inches

Fiberglass withrubber grip

Graphite withrubber grip

Steel with rubbergrip

Steel I- beamencased inplastic withrubber grip

Wood

1-inch-diameterflat steel

1-inch-diametergrooved steel

1.25-inch-diameterflat steel

1.25-inch-diametergrooved steel

12 oz.

16 oz.

20 oz.

24 oz.

Steel claw atnearly a

straigh angleSteel claw at a60 angle with

handleo

Handle Length

Nail RemovalFeature

Angled

Strai ght

8 inches

22 inches

Striking F eature

1 inchgr ooved

1 inchflat

1.25 inchflat

1.25 inchgr ooved

12Oz.

16Oz.24 Oz.

20 Oz.

W ood Fiberglass

SteelI-b eam

Steel

Graphite

Handle Material Weight of Ha mm er H ead

Handle Length

Nail RemovalFeature

Angled

Straight

8 inches

22 inches

Striking Feature

1 inchgrooved

1 inchflat

1.25 inchflat

1.25 inchgrooved

12Oz.

16Oz.24 Oz.

20 Oz.

Wood Fiberglass

SteelI-beam Steel

Graphite

Handle Material Weight of Hammer Head

There should be at least one column in the morphologic box for each generic component in the generic architecture.

No requirement that each generic component have the same number of columns.

Generating creative alternatives for generic components recommended

In some situations more than one choice could be selected for a single instantiated architecture

Automobile Navigational Support systemDirectionSupport

Map &Database

Map, Database,Routing Algorithm

None NoneNone

Horn

Lights

RegularCell Phone

DirectionSensor

StaffedControl Center

ElectroGyros

GPSTransponder

Full GPSSupport

PortablePC(486+)

Car DoorLocks

EmergencySignal

Air Bag

Joy Stick

Control Knob

Voice Output

Acura Navigation System

BMW Navigation System

Oldsmobile Guidestar

Cadillac’s Onstar

Lincoln’s RESCU

RETKI

Button &Key Panel

AutomatedControl Center

32-bitProcessor

4”LCD

6”LCD

6”LCD &Touch Screen

Vehicle’sProcessor

SpecialCell Phone

Localization Processor User I/O Other SystemInterfaces

DirectionSupport

Map &Database

Map, Database,Routing Algorithm

None NoneNone

Horn

Lights

RegularCell Phone

DirectionSensor

StaffedControl Center

ElectroGyros

GPSTransponder

Full GPSSupport

PortablePC(486+)

Car DoorLocks

EmergencySignal

Air Bag

Joy Stick

Control Knob

Voice Output

Acura Navigation System

BMW Navigation System

Oldsmobile Guidestar

Cadillac’s Onstar

Lincoln’s RESCU

RETKI

Button &Key Panel

AutomatedControl Center

32-bitProcessor

4”LCD

6”LCD

6”LCD &Touch Screen

Vehicle’sProcessor

SpecialCell Phone

Localization Processor User I/O Other SystemInterfaces

manual propulsion system for a small boat.Designparameters

Alternative ideas

Input motion

rotating oscillating reciprocating

Input source

one hand

Both hands

One foot Both feet Hand &foot

Input device

Hand crank

pedals lever treadmill

Output device

fin screw propeller Paddle wheel

jet

mechanism gears Belt pulley

Chain & sprocket

linkage pump

Operator position

sitting standing reclining kneeling

manual propulsion system for a small boat.Designparameters

Alternative ideas

Input motion


Input source

one hand

Both hands


Input device

Hand crank


Output device


jet


Chain & sprocket

linkage pump

Operator position


Designparameters

Alternative ideas

Input motion


Input source

one hand

Both hands


Input device

Hand crank


Output device


jet


Chain & sprocket

linkage pump

Operator position


T Asokan ED309

T Asokan ED309

Physical element Option 1 Option2

Emergency component

Audio alarm(‘x’ make)

Visual display(‘Y’ make)

Telephone component

Wireless phone( Nokia/Philips)

Push button phone –terrestrial (BPL/ITI)

Ventilation component

Centralised A/c Exhaust fan ( model X, make Y)

Lighting component Florescent lamp- 2 ft ( Philips, 30w)

LED lamp ( Make X)

T Asokan ED309

GRAPHIC REPRESENTATION OF PHYSICAL ARCHITECTURE

BLOCK DIAGRAM

AircraftDevice

Sensors

CrewCommand

Devices(e.g.,

throttle,pedals?

CrewCommandSensors

CentralController



AircraftDevices

(e.g.,flaps,

ailerons)


AircraftDevice

Sensors

CrewCommand

Devices(e.g.,

throttle,pedals?

CrewCommandSensors

CentralController



AircraftDevices

(e.g.,flaps,

ailerons)


Issues in Physical Architecture Development

Functional Performance

Availability and other “..ilities” as achieved through such characteristics as fault tolerance

Growth Potential and adaptability

Cost

principles of engineering system design

Documents

single physical architecture

physical resources

system physical architecture4

interface architecture

qualification system

aircraft stabilization

specific physical items

engine aircraft