Using UML 2.0 in Real-TimeDevelopment

Kirsten Berkenkötter

University of Bremen

} Introduction} Weaknesses of UML 1.4} New Features of UML 2.0} Weaknesses Reviewed} Conclusion

Introduction} UML 1.4

common standardbasics are easy to learnuseful for communication, specification, documentation

} structural modelingclass diagramsobject diagramscomponent diagramsdeployment diagrams

Introduction} behavioral modeling

use case diagramscollaboration diagrams and sequence diagramsstatechart diagramsactivity diagrams

} real-time developmenthardware-software mutual dependencieshigh reliabilityoften safety-critical background

� high demands on a modeling language

} Introduction} Weaknesses of UML 1.4} New Features of UML 2.0} Weaknesses Reviewed} Conclusion

General Weaknesses of UML 1.4} UML specification

informalsometimes ambiguous

} metamodel4-layer metamodeling approach not followed

} usabilityoverwhelming number of diagrams and elements

General Weaknesses of UML 1.4} diagrams and views

inconsistentno mapping between different diagrams in a model

} composition of modelsno hierarchyinsufficient for large models

Real-Time DependentWeaknesses of UML 1.4

} hardware-software interdependenciesno suffient support

} timing constraintsno syntax and semantics for timing purposes

} communicationno communication structures like ports, connectors,protocols

} Introduction} Weaknesses of UML 1.4} New Features of UML 2.0} Weaknesses Reviewed} Conclusion

New Features of UML 2.0} general

different specification documentsdivision of language core and modeling elements4-layer metamodeling approach realized

} profiles

deriving new elements from metamodelintroducing new terminology, new syntax, new semanticsand constraints, and further information like transformationrules

New Features of UML 2.0} structural modeling

hierarchical modeling in composite structure diagramscommunication structures with ports and connectorscomponents as software components with internal structureand interfaces to the outside

New Features of UML 2.0

New Features of UML 2.0

New Features of UML 2.0} behavioral modeling

fine-grained action modelindependently defined activity diagrams with new featureslike interruptible regions and loopssimple time model and timing diagramsinteractions with new features like alternatives, options,breaks, loops, critical regionsbehavioral and protocol state machines

New Features of UML 2.0

New Features of UML 2.0

New Features of UML 2.0

} structural modeling

class diagramsobject diagramspackage diagramscomponent diagramscomposite structurediagramsdeployment diagrams

} behavioral modeling

use case diagramssequence diagramscommunication diagramsactivity diagramsinteraction overviewdiagramsstatechart diagramstiming diagrams

} Introduction} Weaknesses of UML 1.4} New Features of UML 2.0} Weaknesses Reviewed} Conclusion

ReviewGeneral Weaknesses

} UML specificationmore fine-grainedstill informal

} metamodel4-layer metamodeling approach realizedextension mechanism based on metamodel (profiles)

Review} usability

even more diagrams and elements added� even worse

} diagrams and viewsno change

} composition of modelsimproved by hierarchical modeling with composite structurediagrams

ReviewReal-Time Dependent Weaknesses

} hardware-software interdependenciesdeployment diagrams still insufficientmodeling of hardware as components with ports as accesspoints possible

Review} timing constraints

timing model lacks important features:� no discrete and dense time� no timing zones� no system time� no synchronization between clocks

} communicationports and connectorsprotocol state machines

} Introduction} Weaknesses of UML 1.4} New Features of UML 2.0} Weaknesses Reviewed} Conclusion

Conclusion} improvements

hierarchical modelingcommunication structuresprofiles

} problemsinformal specification � no formal reasoningusability

� profiles best solution for real-time development