Principles of Engineering System Design

Principles of Principles of

Engineering System DesignEngineering System Design

Dr T Asokan

[email protected]

INTRODUCTION TO SYSTEMS DESIGN

Dr T [email protected]

Integration and Qualification

Six functions of Design Process

1. Define System Level Design Problem : - Originating requirements development

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 : Integration and qualification

T Asokan ED309

Integration

It is the process of assembling the system from its components, which must be assembled from their CIs.

Qualification

It is the process of verifying and validating the system design and then obtaining the stake holder’s acceptance of the design.

Consists of verification, validation and acceptance.

Qualification system must be designed simultaneously with the operational system.

The exit criterion for integration and qualification is acceptance of the design by the stakeholders

Verification, Validation and Acceptance

Verification is the determination that the system built was right

Validation determine that the right system was built

Operational ValidityConceptual validityRequirements validityDesign Validity

CI Specs

ComponentSpecs

SegmentSpecs

Element Specs

SystemRequirements

OriginatingRequirements

OperationalConcept

CIs Delivered

ComponentsDelivered

SegmentsDelivered

ElementsDelivered

SystemDelivered

DesignValidity

Acceptablity

Stakeholders’Needs

ConceptualValidity

RequirementsValidity Operational

Validity

DevelopmentalVerification

Systems Engineering

DesignEngineering

Time

SE Vee

CI Specs

ComponentSpecs

SegmentSpecs

Element Specs

SystemRequirements

OriginatingRequirements

OperationalConcept

CIs Delivered

ComponentsDelivered

SegmentsDelivered

ElementsDelivered

SystemDelivered

DesignValidity

Acceptablity


ConceptualValidity

RequirementsValidity Operational

Validity


Systems Engineering

DesignEngineering

Time

SE Vee

CI Specs

Component Specs

Segment Specs

Element Specs

System Requirements

Originating Requirements

Operational Concept

ConceptualValidity


High Level Chain

CIs Delivered

Components Delivered

Segments Delivered

Elements Delivered

System Delivered

Acceptablitiy

Time

Systems Engineering

DesignEngineering

OperationalValidity

SE Vee

Low Level Chain


Conceptual validity,Operational validity,Acceptance testing

Requirementsvalidity, design

validity,verification,

andoperational

validity

RequirementsValidity

DesignV

CI Specs

Component Specs

Segment Specs

Element Specs

System Requirements

Originating Requirements

Operational Concept

ConceptualValidity


High Level Chain

CIs Delivered

Components Delivered

Segments Delivered

Elements Delivered

System Delivered

Acceptablitiy

Time

Systems Engineering

DesignEngineering

OperationalValidity

SE Vee

Low Level Chain


Conceptual validity,Operational validity,Acceptance testing

Requirementsvalidity, design

validity,verification,

andoperational

validity

RequirementsValidity

DesignValidity

Verification

Verification is the matching of CIs, components, subsystems, and the system to their corresponding requirements to ensure that each system has been built right.

For verification to be successful, originating and derived requirements must be testable, that is, the requirements must be single statements that are unambiguous, understandable and verifiable.

Inputs of Stakeholders

System DesignPhase Documentaion

PerformDesignActivities

A1

A2

QualificationSystem DesignDocumentation

Qualification Procedures,Activities, & Models

System Design &Integration

Documentation


SystemIntegrationPhaseDocumentationPerform

Qualification& Integration

Activities

DesignChanges

QualificationSystem

OperationalSystem


System DesignPhase

Documentation


ConductEarly

ValidationA21

A22

A23

A24

EarlyValidationChanges

Derived &OrginatingRequirements

OperationalConcept

Acceptanceor Rejection

AcceptanceCriteria &Thresholds

DesignChanges

SystemIntegration

PhaseDocumentation

VerificationChanges

EarlyValidationDocument

VerificationDocument Validation

Changes

“Built -to”CIs Conduct

Integration &Verification

ConductValidation

Pre-ProductionPrototypes

VerificationData

ValidationDocument

ValidationData Conduct

AcceptanceTesting

AcceptanceChanges

AcceptanceTestingDocument

OperationalSystem

Bottom-up integration process

( )


System DesignPhase Documentaion


A1

A2



System Design &Integration

Documentation


SystemIntegrationPhaseDocumentationPerform

Qualification& Integration

Activities

DesignChanges

QualificationSystem

OperationalSystem


System DesignPhase

Documentation


ConductEar ly

ValidationA21

A22

A23

A24

EarlyValidationChanges

Derived &OrginatingRequirement s

OperationalConcept

Acceptanceor Rejection

AcceptanceCriteria &Thresholds

DesignChanges

SystemIntegrat ion

PhaseDocumentation

VerificationChanges

EarlyValidationDocument

VerificationDocument Validation

Changes

“Built -to”CIs Conduct

Integration &Ver ification

ConductValidation

Pre-ProductionPrototypes

Ver ificationData

ValidationDocument

ValidationData Conduct

AcceptanceTesting

AcceptanceChanges

AcceptanceTestingDocument

OperationalSystem

Bottom-up integration process

( )

Integration

1. Perform component integration and verification

2. Perform subsystem integration and verification

3. Perform system integration and verification

Principal Integration Processes

Bottom up- Begins with CIs- After each CI is tested, the components

comprising multiple CIs are tested- Process is continued until entire system is

assembled and tested

- Easier to detect flaws in tiniest pieces of the system

- Test conditions are easier to create- Major errors are not caught until the end

Top Down- Top level module- Lower levels simulated by stubs - Stubs later replaced by modules- Early demonstration of the system

- More productive major flaws occur at the top of the

system

- Stubs have to be developed

- Representation of test case in stubs will be difficult

Big Bang (Software industry)

- Untested CIs are assembled and the combination is tested- Commonly used and maligned approach

- Immediate feedback on the status of system elements is provided

- Little or no pre-test planning or training is required

- Source of error is difficult to trace

Functions in IntegrationComponent Level

1. Inspect and test the CI

2. Identify and fix any correctable deficiency found in the first function

3. Assess the impact of any uncorrectable deficiency found in the first function

4. Redesign the subsystem/CI to address unacceptable impacts of any uncorrectable deficiency found in the third function

5. Modify the baseline of the design to account any fixes (function 2) or acceptable impacts (requirements change from function 3)

6. Integrate with the next CI and repeat till all CIs are integrated.

Integration is a bottom up approach

Inspect and test the CI

Identify and fix any correctible

deficiencies

Assess the impact of any

uncorrectable deficiencies

Redesign the CI to address

deficiencies

Redefine the baseline

Integrate with the next CI

Qualification procedures,Activities & Models

Derived &Originating

Requirements

Originating& SystemRequirementsDocuments

VerificationChanges

CI TestResults

CI TestResults

VerificationDocument

Componen LevelDesign Documents Subsystem Level

Design Documents

“Built-to”CIs

PerformComponentIntegration &Verification

A221

A222

A2211

A2212

A2213

A2214

A2215

A2216

A223

CI VerificationChanges

“Built-to”Components

ComponentVerificationChanges

ComponentVerificationDocuments

SubsystemVerificationDocuments

SubsytemVerificationChanges

ComponentTestResults

“Built-to”Subsystems

System-GeneratedSubsystemRegressionQualification

Subsystem-GeneratedComponentRegressionQualification

System-GeneratedComponentRegressionQualification

PerformSubsystem


PerformSystem


SystemVerificationDocument

VerificationData

SubsystemTestResults

System LevelRegressionQualification


Component LevelDesign Documents

“Built-to”CIs

Subsytem-GeneratedComponentRegressionQualification


Inspect&

Verify CI DeficientCI Discrepancy

Reports

Identity & FixCorrectable

CIDeficiencies Assess

Impact ofUncorrectable

CIDeficiencies

RedesignCI

Modifiy CIBaseline

Integratewith

Next CI

Corrected CI

ClearedCI

Uncorrected CI

Redesigned CI

Approval toContinueIntegration

UnacceptableImpact

ImpactStatement

AcceptableImpact

CIEngineeringChanges

BaselineChanges




Cleared CI

Inspect and test the CI

Identify and fix any correctible

deficiencies

Assess the impact of any uncorrectable

deficiencies

Redesign the CI to address

deficiencies

Redefine the baseline

Integrate with the next CI

Qualification procedures,Activities & Models

Derived &Originating

Requirements

Originating& SystemRequirementsDocuments

VerificationChanges

CI TestResults

CI TestResults

VerificationDocument

Componen LevelDesign Documents Subsystem Level

Design Documents

“Built-to”CIs

PerformComponentIntegration &Verification

A221

A222

A2211

A2212

A2213

A2214

A2215

A2216

A223



ComponentVerificationChanges


SubsystemVerificationDocuments

SubsytemVerificationChanges

ComponentTestResults

“Built-to”Subsystems

System-GeneratedSubsystemRegressionQualification

Subsystem-GeneratedComponentRegressionQualification


PerformSubsystem


PerformSystem


SystemVerificationDocument

VerificationData

SubsystemTestResults

System LevelRegressionQualification


Component LevelDesign Documents

“Built-to”CIs

Subsytem-GeneratedComponentRegressionQualification


Inspect&

Verify CI DeficientCI Discrepancy

Reports

Identity & FixCorrectable

CIDeficiencies Assess

Impact ofUncorrectable

CIDeficiencies

RedesignCI

Modifiy CIBaseline

Integratewith

Next CI

Corrected CI

ClearedCI

Uncorrected CI

Redesigned CI

Approval toContinueIntegration

UnacceptableImpact

ImpactStatement

AcceptableImpact

CIEngineeringChanges

BaselineChanges




Cleared CI

Continue until everysubsystem has been

integratedYes

Subsystem IntegrationComplete

Inspect and TestSubsystem

NoDeficient

Subsystem

Yes

Modify and FixCorrectableDeficiencies

RemainingDeficiencies

No

Yes

Modify Baseline

Assess Impact ofUncorrectable

Deficiences

DeficienciesUnacceptable

No

Yes

Redesign Subsystem

Logic diagram for subsystem integration


1

IT

2.3.1

Inspect& Test

Subsystem

LP

cleared subsystem

deficientsubsystem

2.3.2Identify & FixCorrectableDeficiencies

correctabledef.

uncorrectabledef.

2.3.3Assess Impact

ofUncorrectable..

acceptableimpact

unacceptableimpact

2.3.4

RedesignSubsystem

OR

OR

if deficiency is fixed or redesigned

for each subsystem

2.3.5

ModifyBaseline

OR LP IT

2.3.6Integratewith NextSubsystem

2.1Perform

ComponentIntegration


1

IT

2.3.1

Inspect& Test

Subsystem

LP

cleared subsystem

deficientsubsystem

2.3.2

Identify & FixCorrectableDeficiencies

correctabledef.

uncorrectabledef.

2.3.3Assess Impact

ofUncorrectable..

acceptableimpact

unacceptableimpact

2.3.4

RedesignSubsystem

OR

OR

if deficiency is fixed or redesigned

for each subsystem

2.3.5

ModifyBaseline

OR LP IT

2.3.6Integratewith NextSubsystem

2.1Perform

ComponentIntegration