© 2004 by Carnegie Mellon University

The Society of Automotive Engineers (SAE) Architecture Analysis & Design Language

(AADL) Standard

An International Industry Standard for Embedded & Real-time Systems

www.aadl.infowww.aadl.info 2© 2004 by Carnegie Mellon University

SAE AADL StandardAn Enabler of Predictable Model-Based

System Engineering

• Notation for specification of task and communication architectures of Real-time, Embedded, Fault-tolerant, Secure, Safety-critical, Software-intensive systems

• Fields of application: Avionics, Automotive, Aerospace, Autonomous systems, …

• Based on 15 Years of DARPA funded technologies

• Standard approved and published Nov 2004

• www.aadl.info

www.aadl.infowww.aadl.info 3© 2004 by Carnegie Mellon University

SAE AS-2C AADL Subcommittee

• Bruce Lewis (US Army AMRDEC): Chair• Peter Feiler (SEI): technical lead, author & editor• Steve Vestal (Honeywell): co-author• Ed Colbert (USC): UML Profile of AADL• Joyce Tokar (Pyrrhus Software): Ada & C AnnexOther Voting Members• Boeing, Rockwell, Honeywell, Lockheed Martin,

Raytheon, Smith Industries, General Dynamics, Airbus, Axlog, European Space Agency, TNI, Dassault, EADS, High Integrity Solutions

Coordination with • NATO Aviation, NATO Plug and Play, French

Government COTRE, SAE AS-1 Weapons Plug and Play, OMG UML & SysML

www.aadl.infowww.aadl.info 4© 2004 by Carnegie Mellon University

Typical Software Development Process

Requirements Analysis

Design Implementation Integration

Manual, Paper Intensive, Error Prone, Resistant to Change

High Risk System Integration

High Development & Maintenance Cost

Little Insight

www.aadl.infowww.aadl.info 5© 2004 by Carnegie Mellon University

Model-Based System Engineering

RequirementsAnalysis

System Integration

Predictive Analysis Early In & Throughout Life Cycle

Architecture-Driven Development

Architecture Modeling & Analysis

Rapid Integration Predictable Operation

UpgradeabilityReduced Cost

www.aadl.infowww.aadl.info 6© 2004 by Carnegie Mellon University

Ambulatory

InformationFusion

Supply Chain

Mechanized

Sensor& SignalProcessing

System Integration•Runtime System Generation• Application Composition• System Configuration

Devices Memory Bus Processor

AADL-Based System Engineering

AutomaticTargetRecognition

Guidance& Control

System Analysis• Schedulability• Performance• Reliability• Fault Tolerance• Dynamic Configurability

Architecture Modeling

Abstract, but Precise

HTTPSDBGPS Ada Runtime

Execution Platform

. . . . . . . . . .

Application Software

SoftwareSystemEngineer

ComposableComponents

Predictive System

EngineeringReduced

Development & Operational Cost

www.aadl.infowww.aadl.info 7© 2004 by Carnegie Mellon University

A Partitioned Portable Architecture

Strong Partitioning • Timing Protection• OS Call Restrictions• Memory Protection

Interoperability/Portability• Tailored Runtime Executive• Standard RTOS API• Application Components

Real-Time Operating System

Application Software

Component

Embedded Hardware Target

AADL Runtime System

Application Software

Component

Application Software

Component

Application Software

Component

www.aadl.infowww.aadl.info 8© 2004 by Carnegie Mellon University

Key AADL Standard Elements

• Precise semantics for AADL components– Quantitative analysis of operational real-time system properties

• Core AADL notation standard– Common real-time systems modeling notation across

organizations

• AADL Meta model & XMI/XML standard– Model interchange & tool interoperability

• UML profile for AADL– Transition path for practitioner community

• Standard compliant AADL extensions & annexes– Accommodation of new & project-specific analyses

www.aadl.infowww.aadl.info 9© 2004 by Carnegie Mellon University

XMI/XML Based Tool Interoperability

TextualAADL

Co-residenttool

AADL XMLTool Interface

Tool-specificrepresentation

GraphicalAADLSemantic

Checking

AADL Front-end

Declarative AADL Model

AADL Instance Model

Graphical Layout Model

Persistent XMLdocument

Tool-specific XML Representation

Convert

Convert

Parser Graphical View

Name Resolution

www.aadl.infowww.aadl.info 10© 2004 by Carnegie Mellon University

Two-Tier Tool Strategy

• Open Source AADL Tool Environment (OSATE)– Developed by SEI– Low entry cost solution (no cost CPL)– Multi-platform support based on Eclipse– Vehicle for in-house prototyping of project specific

architecture analysis– Vehicle for architecture research with access to industrial

models & industry exposure to research results

• Commercial Tool Support– UML tool environment extension based on UML profile– Extension to existing modeling environment with AADL

export/import– Analysis tools interfacing via XML or XML to native filter

www.aadl.infowww.aadl.info 11© 2004 by Carnegie Mellon University

AADL/UML Relationship

UML 2.0

UML-RTPerformanceTimeliness

UML 1.4Detailed design

AADLCore

Dependability

Security

AADL AnnexesUML Working Groups

AADLUML Profile

AADL AnnexesUML Working Groups

(Embedded)Software System

Engineering

System Engineering

SysMLTo Be submitted to OMG for Adoption

www.aadl.infowww.aadl.info 12© 2004 by Carnegie Mellon University

AADL In Use

www.aadl.infowww.aadl.info 13© 2004 by Carnegie Mellon University

Benefits

• Model-based system engineering benefits

• Benefits of AADL as SAE standard

Predictable runtime characteristics addressed early and throughout life

cycle greatly reduces integration and maintenance effort

AADL as standard provides confidence in language stability, broad adoption, and strong tool support