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  Interfaces At an early stage Need to deal with trade-offs Need to consider ‘physical’ aspects – eg Submarines Need to cover performance, reliability, - ‘ilities’.

Models SysML UML Systems of Systems System Design Software Design Satisfies Where does SysML fit in Supports Architecture 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 Diagrams Diagram Structure ClassComponentObject PackageDeployment Behaviour State MachineUse CaseActivity Interaction CommunicationSequence UML 1.x

UML 2.0 Diagrams SysML Diagram Structure ClassComponentObject PackageDeployment Composite Structure Behaviour State MachineUse CaseActivity Interaction CommunicationSequence Timing Interaction Overview UML 1.x UML 2.0

SysML Diagrams SysML Diagram Structure Package SysML 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 Diagrams What the system needs to do.

Extended Activity Diagrams Swim-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