SysML Awareness

John Davies BSc, PhD, CEng, FIET.

Objectives

Why am I here? To raise awareness of the SysML To show you some of the features of SysML To try and explain the benefits of using the SysML.

But I am not an expert I am not a tool vendor I think SysML is important

•What is it ?

•The Systems Modelling Language

•What is it used for ?

•Modelling System Designs !

•What is it like ?

•A bit like UML (The Unified Modelling Language)

Introduction:

•Since late 90’s – UML has become a widely used as a general purpose visual modelling language with software engineers,

•Up to then it had a Software focus

•In 2003 the Object Management Group (OMG) decided to pursue UML for systems engineering, with a request for proposals.

•The SysML group were successful, proposing a language based on UML 2.0.

•Currently SysML 1.0 is in its approval loop

History

Where to find SysML

•To provide a “standard modelling language for systems engineering

•Allow systems engineers to:

•Analyse, Specify, Design, and Verify complex systems.

•To improve communications between:

•Engineering Disciplines, i.e. Systems, Software, Hardware

•Engineering Tools

•To use UML 2.0 as much as possible and avoid making unnecessary changes.

SysML Goals:

Who is involved in defining SysML

•American Systems Corporation

•ARTISAN Software Tools

•BAE SYSTEMS

•The Boeing Company

•Ceira Technologies

•Deere & Company

•EADS Astrium GmbH

•EmbeddedPlus Engineering

•Eurostep Group AB

•Gentleware AG

•I-Logix, Inc.

•International Business Machines

•International Council on Systems Engineering

•Israel Aircraft Industries

•Lockheed Martin Corporation

•Motorola, Inc.

•Northrop Grumman

•oose.de Dienstleistungen für innovative Informatik GmbH

•PivotPoint Technology Corporation

•Raytheon Company

•Telelogic AB

•THALES

Basic System Design

Define the system boundary/context Identify what the system has to do Identify the major parts of the system Identify/allocate which part does what Check that the parts working together achieve

the overall needs of the system

Why is System Engineering/Design different to Software Engineering/Design?

Starts from ‘Woolly ideas’ – ‘Concepts’ Low level of ‘design maturity’

Need to work with Context Partitioning – to sub-systems High-level Functionality Allocation InterfacesAt an early stage

Need to deal with trade-offs Need to consider ‘physical’ aspects – eg Submarines Need to cover performance, reliability, - ‘ilities’.

Models

Models

SysML

UML

Systems of Systems

System Design

Software Design

Sat

isfi

esS

atis

fies

Where does SysML fit in

SupportsArchitecture

Modelling

From UML to SysML.

UML collation of Object-Oriented methods and diagrams

UML 2.0 improved, better defined, meta-model Standard application/extension mechanisms ‘Profiles’

SysML Defined ‘Profile’ for Systems Engineering Uses sub-set of ‘Standard’ UML 2.0 plus specific extensions for Systems

Engineering

UML 1.x DiagramsDiagram

Structure

Class Component Object

PackageDeployment

Behaviour

State MachineUse CaseActivity

Interaction

CommunicationSequenceUML 1.x

UML 2.0 DiagramsSysML

Diagram

Structure

Class Component Object

PackageDeploymentComposite Structure

Behaviour

State MachineUse CaseActivity

Interaction

CommunicationSequence

TimingInteractionOverview

UML 1.x

UML 2.0

SysML DiagramsSysML

Diagram

Structure

PackageSysML

Internal Block

SysML:Requirements

SysML:Parametric

Behaviour

State MachineUse CaseActivity

Sequence

SysML:Block Definition

UML 1.x

UML 2.0

SysML:

Interaction

New Diagrams Requirements Diagrams

Requirements hierarchies Requirements tracing diagrams Overlap with Requirements Management Tools – but may be needed on some

projects ‘Two-way’ exchange with Requirements Management Tools

Parametric Diagrams Parameter equations/ Constraints /Parameter limits E.g Time to react to an incoming threat

Detection/Identification: power/time/resolution Assessment/allocation/fire control Weapon fire/transit time to target Range/speed of target

Block Diagrams Structure diagram for System Elements Can use for different structures

Physical structure System/sub-system structure Security structure Etc.

Extended Diagrams

Activity Diagram Allocation added - identify ‘who does what’

Timing Diagram Allocation added - as above

State Machine Diagram Can have more than one machine on the diagram

Standard – Use Case DiagramsWhat the system needs to do.

Extended Activity DiagramsSwim-lanes to identify who does what.

New Block Diagram – System Architecture

New Requirements Diagram.

New Parametric Diagrams.

Some Issues

What ‘level’ to use SysML Illustration Supporting information Complete specification

How to show ‘This is the general overview’ and ‘This is the refined/detailed view’ in the same model

Which diagrams to use on a specific project Don’t need to use them all But need to get a ‘complete picture’

How to link to other Systems Activities

Tool Suppliers

Established tool vendors for UML Artisan Studio Telelogic – Tau G2 Sparx Systems …..

All support ‘most’ in SysML Some generalised diagrams can be applied for

specific use

In Conclusion

SysML is the emergent standard for Systems Design Version 1.0 awaiting approval

Tool support available from Standard UML 2.0 tool vendors

System Design is not all of Systems Engineering but SysML will improve things…

Thank you