UML for space systems engineering status and perspective 2nd ESA Space Systems Design, Verification

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UML for space systems engineering- status and
perspective 2nd ESA Space Systems Design,
Verification AIT Workshop15-16 April 2003
Harald EisenmannJens EickhoffAstrium
GmbHFriedrichhafenHarald.Eisenmann_at_astrium-spac
e.comJens.Eickhoff_at_astrium-space.com
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Model-based Development (functional/operational)
D

e
s
a
h
P
Execution
Phase C
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Need for

• Models that can serve as
• Specification model
• Test reference (and are therefore executable)
• Models independent of a specific execution
  platform
• Modeling language which provides different layers
  of abstraction
• Efficient data exchange for the models
• Models can be associated to the data (i.e.
  project/engineering databases) which is developed
  as part of the S/C process
• Modified engineering process which supports both
• Procurement specification
• Model development

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A first UML diagram
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OMG Object Management Group

• Forum to create open integration standards for
  computer industry
• OMG provides standardization platform
  (organization, process)
• Decision taken by members (companies,
  organizations, govermental agencies)
• Adopted Standards freely available
• Most well known Standards
• CORBA (Common Object Request Broker Architecture)
• UML (Unified Modeling Language)
• XMI (Xml-Meta model-Interchange)
• MDA (Model-Driven-Architecture)

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UML Facts - Background

• Motivation
• OO programming languages industrial use (late 80)
• Need for additional design methodologies
• Different approaches Booch-Method, OMT, OOSE,
  others (early 90s )
• Need for harmonization of approaches
• Attempt to set-up Unified Method -gt Unified
  Modeling Language
• OMG
• Current Status
• Most frequently used modeling notation for S/W
  systems
• Version 1.5 adopted
• Version 2.0 is expected in 2003

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A Quick Tour of UML
DynamicModeling
Use-CaseModeling
Statechart Modeling
ImplementationModeling
ActivityModeling
Static Structure

• Class Diagram
• classes, their internal structure
• packages and subsystems
• relationships among classes
• Object Diagram
• instance of class diagram
• snapshot at a point of time

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A Quick Tour of UML
Static Structure
Use-CaseModeling
Statechart Modeling
ImplementationModeling
ActivityModeling
DynamicModeling

• Sequence Diagram
• shows interaction between classes and object
  in a time ordered way
• Collaboration Diagram
• similar to sequence diagrams but emphasis on
  objects and their collaboration (data flow)

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A Quick Tour of UML
Static Structure
DynamicModeling
Statechart Modeling
ImplementationModeling
ActivityModeling
Use-CaseModeling

• diagram shows
• actor of a system
• typical use cases
• and their relationship
• level of detail comparable to URD

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A Quick Tour of UML
Static Structure
DynamicModeling
ImplementationModeling
ActivityModeling
Use-CaseModeling
Statechart Modeling

• models discrete state-transition behavior
• based on Harrel statechart notation
• can be hierarchically nested
• decisions

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A Quick Tour of UML
Static Structure
DynamicModeling
Statechart Modeling
ImplementationModeling
Use-CaseModeling
ActivityModeling

• variant of state-chart which emphasizes flow
  of information
• focuses on control flow or processes
• junction, fork, join and synchronizations
  allow modeling of concurrency

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A Quick Tour of UML

• Additional Features
• Extensibility Mechanisms
• Stereotypes
• Constraints
• Tagged Values
• OCL (Object Constraint Language)
• XMI (XML Meta-model Interchange) data exchange

Static Structure
DynamicModeling
Statechart Modeling
ImplementationModeling
ActivityModeling
Use-CaseModeling
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UML Modeling Layers
Hard-wired definition of the meta-model
MOF
M3 (MOF)
Meta-Model
Definition of syntax and semantic of the M1 layer
(adaptable)
M2 (Meta Model)
Model
Model of a specific Car, Spacecraft,
M1 (Model)
Data
Model execution, data archive, file
M0 (Data)
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UML Meta-Model

• UML Meta Model is used to
• Describe syntax of the UML
• Provide mean for data exchange
• UML meta-model is expressed through UML class
  diagrams
• Elements in the meta-model(m2) describe modeling
  elements of the modeling layer below (m1)
• The OCL can be used to express additional
  constraints
• UML allows the extension/tailoring of the meta
  model -gt UML-Profile

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UML Profile

• Extension/tailoring of the UML Meta Model for a
  specific problem domain
• Additional modeling elements
• Additional associations
• Constraining of information
• Meta model exchange can exchanged using XMI
• Among others OMG adopted the following profiles
• CWM (common warehouse modeling)
• EDOC (enterprise distributed object computing)
• Real-time
• Systems Engineering (in definition)

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OMG/Model-Drive Architecture
MOF
Meta-M odel
Model
Transformation Model to Data
Data
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UML Profile for Systems Engineering (Goals)

• Need for standardized modeling language for
  system engineering purposes ? INCOSE OMG
  liaison to adapt UML for systems engineering
  needs
• Goals of a UML for systems engineering are
• Support the analysis, specification, design and
  verification of complex systems
• Support modeling of system level requirements
• Allow integration of domain specific extensions
  (different application domains)
• Support analysis of a system such as analytical
  models

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UML for Systems Engineering (Requirements)

• Structure (subsystems, h/w, s/w, data, procedure,
  user, )
• Interconnections
• Ports
• Behavior
• Functional transformation of inputs to outputs !!
• State-based, function-based
• Control
• Property (type definition, its values and units,
  )
• Requirement (classification and properties)

Is it still just object-oriented?
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UML Modeling Framework
M3
MOF
Meta-model data (schema)
M2
Meta-Model
M1
Model
M0
OPS Sim
SVF
DBMS
XML
RTB
Model data
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Checklist against Problems

• Efficient engineering process which supports
• Procurement specification
• Model development
• Models can serve as
• Specification model
• Test reference (and are therefore executable)
• Models are independent of a specific execution
  platform
• Modeling language which provides different layers
  of abstraction
• Efficient data exchange for the models
• Models can be associated to the data (i.e.
  project/engineering databases) which are
  developed as part of the S/C process

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What remains to do?

• Evaluation of the UML Systems Engineering Profile
  in the Space Engineering Context
• Combination of Systems Engineering Profile and
  CWM and EDOC to have consistent modeling
  environment with
• Data archive schemas
• Data exchange schemas
• Bridge the gap between UML/XML world to STEP
  (i.e. AP233)
• Model-based Development
• Execution Support (-gt Model-based debugging!)
• Visualization
• Relationship to ECSS?