Model Driven Systems Model Driven Systems Engineering:Engineering:

Linking the Linking the ““VeeVee””Tim Tritsch – Vitech Corporation

Janice Magill - NAVAIRJames Newbury – NAVAIR

NDIA Systems Engineering Conference24 October 2006

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TopicsTopics

• The “Vee” chart – Review

• Model Driven Systems Engineering – Overview

• The Advanced Arresting Gear Program

• AAG System Model Development

• AAG Test Program

• Description of Verification Method Structure

• Relating Requirements to Verification Methods

• Summary and Conclusions

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Forsberg and Mooz Forsberg and Mooz ““VeeVee””

• Provides basic map of a system development cycle• Implies each phase of design definition has associated

integration and qualification activities• Principles adopted in DoD acquisition guidelines and

many ACAT programs– ANSI/EIA- 632 (Processes for Engineering a System)– Defense acquisition’s Integrated Defense Acquisition,

Technology and Logistics Life Cycle Management Framework

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Requirements Development and QualificationRequirements Development and Qualification

Has been extended to include phased development strategies.

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Model Driven Systems EngineeringModel Driven Systems Engineering

• Complete System Definition Capture in System Model– Concept of Operations– System requirements– System behavior– System structure– Component interaction (I/O)– Verification, Validation, and Qualification tasks and

methods– Relevant relationships between all the above

• Consistency in documentation • Multiple views of the System (Textural and/or Graphical)

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Advanced Arresting Gear EnvironmentAdvanced Arresting Gear Environment

Washington

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Challenges of an Aircraft CarrierChallenges of an Aircraft Carrier

• A typical airport has a runway over a mile, an aircraft carrier has less than 800 feet.

• On a carrier, the runway moves with the waves. • On a carrier, the hot, wet, salty environment is destined

to corrode any equipment.• On a carrier, there are stringent equipment requirements

– Space limitations– Rigorous shock and vibration standards– Strict electromagnetic interference and compatibility

requirements • On a carrier, equipment is repaired and maintained by 19

year olds working 12 hour shifts.

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Advance Arresting GearAdvance Arresting Gear

• Naval Air System Command (NAVAIR) and General Atomics (GA) have taken the challenge to develop a new arresting system that will take aircraft carriers into the 21st century

• The AAG program – Has completed a technology demonstration phase– Was designated ACAT II at MS B in October 2004– Is currently in System Development and Demonstration– Has Low Rate Initial Production slated for October 2009

• The team is jointly applying a Model Based Approach to manage the Advance Arresting Gear system definition.

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AAG System Model DevelopmentAAG System Model Development

• NAVAIR –– Stakeholder Requirements identified, collected, and defined to

develop Operational Capability Document (OCD)– Chose CORE™ as the CASE tool to manage system technical

requirements and produce System Specification part of Request for Proposal (RFP)

• Performance Requirements• Constraints• External System Interfaces• Verification Methods for all requirements

– Model Provided as GFI• Traceability to OCD• System Functional and Physical Architecture• Data Item Flow from External Systems

– Modified in transition to Capability Design Description (CDD)

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AAG System Model Development (cont.)AAG System Model Development (cont.)

• General Atomics –– Required to use “A CASE tool”, chose CORE™ to take full

advantage of GFI system model – Developed physical and functional representation at the

subsystem and component level • Derive Performance Requirements• Derive Design Constraints• Define Internal Interface Requirements• Define Internal Data flow• Flow Down of System Constraints (i.e. reliability,

maintainability, and human factors)

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AAG Physical HierarchyAAG Physical Hierarchy

SYS.1Advanced

Arresting GearSystem

SYS.1.1Cross DeckPendant

Subsystem

SYS.1.2Energy

AbsorberSubsystem

SYS.1.2.1

Electric Motor

SYS.1.2.2

MechanicalBrake

SYS.1.2.3

PurchaseCable Drum

SYS.1.2.4

Water Twister

SYS.1.3DynamicControl

Subsystem

SYS.1.4

Drive FairleadSubsystem

SYS.1.5Power

ConditioningSubsystem

SYS.1.6

Prime PowerSubsystem

SYS.1.7WorkstationManagementSubsystem

SYS.1.7.1

Air BossDisplay

SYS.1.7.2Arresting Gear

OperatorControl Station

SYS.1.7.3

HealthMAP

SYS.1.7.4Retract

OperatorControl Station

SYS.1.7.5

SupervisoryControl Server

SYS.1.8Thermal

ManagementSubsystem

SYS.1.9Shock

AbsorberSubsystem

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AAG System Model Development (cont.)AAG System Model Development (cont.)

• System Model used by General Atomics to– Ensure flow down and traceability to procurement

specification – Enabled traceability to trade studies and design analysis

• Functional Baseline for Initial FMECA– Produced:

• System Specification• Subsystem Specifications• Components Specifications• Software Requirements Specifications• Test and Evaluation Plans

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AAG Test ProgramAAG Test Program

• The AAG program has applied a cohesive integration and test strategy to verify the engineering development of the system. – Component, subscale, and prototype level to verify

concepts, validate the developmental arrestment model, and reduce risks

– Integration and reliability testing will reduce risk through integration of major components

– Environmental tests to ensure the system is qualified for the intended operational environment

– System level tests at Jet Car Test Site and Remote Aircraft Landing Site

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AAG Test DocumentationAAG Test Documentation

• For the AAG program, – The overall test strategy is captured Test and

Evaluation Master Plan (TEMP) – The developmental test framework is captured in the

Test Evaluation Plans (TEP) in accordance with test strategy

– Detailed procedures are captured in the individual test directives

– Developmental tests will be documented in a series of test reports

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Associating Requirements to Verification Associating Requirements to Verification MethodsMethods

REQUIREMENT IDENTIFICATION(Function, Performance Index, Constraint)

REQUIREMENT IDENTIFICATIONREQUIREMENT IDENTIFICATION(Function, Performance Index, Constraint)(Function, Performance Index, Constraint)

•TD Qualification Analysis

– System Simulation

– Engineering Analysis

– Reliability Analysis

•SDD Qualification Analysis

– System Simulation

– Engineering Analysis

– Reliability Analysis

•SDD Inspection Test

•SDD Controls / HealthMAPSoftware

– Software Unit Test

– Software Integrated Test

•SDD Prototype Subsystem & Component Tests

•SDD Integration & Extended Reliability Tests

•SDD Fairlead Tests & JCTS Commissioning

•SDD JCTS Functional & Performance Demonstration Tests

•SDD RALS Functional & Performance Demonstration Tests

•SDD Maintainability Tests

•Environmental Qualification Tests

– Humidity, Salt Fog, Shock, Vibration, Rain UE, Rain CE, Solar Radiation, Icing, Fluid Contamination, Sand & Dust, EMI, Extreme Temperatures

•Preparation For Delivery / Shipment

VERIFICATION METHOD SELECTIONVERIFICATION METHOD SELECTIONVERIFICATION METHOD SELECTION

ANALYSISANALYSISANALYSIS INSPECTION, DEMONSTRATION, & TESTINSPECTION, DEMONSTRATION, & TESTINSPECTION, DEMONSTRATION, & TEST

REQUIREMENT IDENTIFICATION(Function, Performance Index, Constraint)

REQUIREMENT IDENTIFICATIONREQUIREMENT IDENTIFICATION(Function, Performance Index, Constraint)(Function, Performance Index, Constraint)

•TD Qualification Analysis

– System Simulation

– Engineering Analysis

– Reliability Analysis

•SDD Qualification Analysis

– System Simulation

– Engineering Analysis

– Reliability Analysis

•SDD Inspection Test

•SDD Controls / HealthMAPSoftware

– Software Unit Test

– Software Integrated Test

•SDD Prototype Subsystem & Component Tests

•SDD Integration & Extended Reliability Tests

•SDD Fairlead Tests & JCTS Commissioning

•SDD JCTS Functional & Performance Demonstration Tests

•SDD RALS Functional & Performance Demonstration Tests

•SDD Maintainability Tests

•Environmental Qualification Tests

– Humidity, Salt Fog, Shock, Vibration, Rain UE, Rain CE, Solar Radiation, Icing, Fluid Contamination, Sand & Dust, EMI, Extreme Temperatures

•Preparation For Delivery / Shipment

VERIFICATION METHOD SELECTIONVERIFICATION METHOD SELECTIONVERIFICATION METHOD SELECTION

ANALYSISANALYSISANALYSIS INSPECTION, DEMONSTRATION, & TESTINSPECTION, DEMONSTRATION, & TESTINSPECTION, DEMONSTRATION, & TEST

Model Based Approach Developed the Test Plans and Specification Qualification Section

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Map of Elements for Test PlanningMap of Elements for Test Planning

RequirementRequirementRequirement

Instrumentation, facilities, and support equipment

i.e. Environmental Qualification, Functional Demonstration

Functions, performance indices, interface, links, and constraints

Test management, Test Directive, procedures, training, FRACAS process, safety processes, security processes, reporting requirements, environmental requirements, installation requirements

i.e. test director, reliability personnel, safety personnel, environmental representative

verified by

satisfied by

constrains,allocated to,traces to,exhibited by

uses configuration defined by assigned to

~ Component

Verification Method(s)Verification Method(s)Verification Method(s)

Verification Event(s)Verification Event(s)Verification Event(s) Test ArticlesTest ArticlesTest Articles

Test ConfigurationsTest ConfigurationsTest Configurations Test ProceduresTest ProceduresTest Procedures Responsible OrganizationsResponsible Responsible

OrganizationsOrganizations ScheduleScheduleSchedule

~ Attribute

RequirementRequirementRequirement

Instrumentation, facilities, and support equipment

i.e. Environmental Qualification, Functional Demonstration

Functions, performance indices, interface, links, and constraints

Test management, Test Directive, procedures, training, FRACAS process, safety processes, security processes, reporting requirements, environmental requirements, installation requirements

i.e. test director, reliability personnel, safety personnel, environmental representative

verified by

satisfied by

constrains,allocated to,traces to,exhibited by

uses configuration defined by assigned to

~ Component

Verification Method(s)Verification Method(s)Verification Method(s)

Verification Event(s)Verification Event(s)Verification Event(s) Test ArticlesTest ArticlesTest Articles

Test ConfigurationsTest ConfigurationsTest Configurations Test ProceduresTest ProceduresTest Procedures Responsible OrganizationsResponsible Responsible

OrganizationsOrganizations ScheduleScheduleSchedule

~ Attribute

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Lessons LearnedLessons Learned

• Aggressive development schedule reduced adherence to :– “Bottom to top” test plan development, Integration test

plans completed before component requirements (and verification plans) fully developed

– Program leveraged integrated tests for the verification of a majority of the component requirements

• Through the process of assigning requirements to verification methods, the need for a substantial integrated test was clear– Many requirements of component tests not achievable

at component level due to design parameters beyond test fixture capability

– Integration test phase expanded to include additional major components of the system for risk reduction

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ConclusionsConclusions

• The model-based approach increases confidence that the system design solution is on track to meet requirements

• Discipline of the model-based approach ensures that performance capability and reliability are designed into the system early

• Development of the TEPs provided the program and stakeholders early visibility of the derived requirements, the planned verification, and the resources required

• Managers, design engineers, systems engineers, test engineers, logistics, etc. all contributed to the same product baseline

• Early identification of verification requirements provided better scheduling and resource budgeting