18 research outputs found
Modelling Recursive Calls with UML State Diagrams
One of the principal uses of UML is the modelling of synchronous object-oriented software systems, in which the behaviour of each of several classes is modelled using a state diagram. UML permits a transition of the state diagram to show both the event which causes the transition (typically, the fact that the object receives a message) and the objectâs reaction (typically, the fact that the object sends a message). UMLâs semantics for state diagrams is ârun to completionâ. We show that this can lead to anomalous behaviour, and in particular that it is not possible to model recursive calls, in which an object receives a second message whilst still in the process of reacting to the first. Drawing on both ongoing work by the UML2.0 submitters and recent theoretical work [1,6], we propose a solution to this problem using state diagrams in two complementary ways
Exploration games for UML software design
The Unified Modeling Language (UML) has become the standard language
for the design of object-oriented software systems over the past
decade. Even though there exist various tools which claim to support
design with UML, their functionality is usually focused on drawing UML
diagrams and generating code from the UML model. The task of choosing
a suitable design which fulfils the requirements still has to be
accomplished by the human designer alone.
The aim of this thesis is to develop concepts for UML design tools
which assist the modeller in improving the system design and
requirements incrementally. For this approach a variant of formal
games called exploration games is introduced as underlying
technique. Exploration games can be defined on the basis of incomplete
and imprecise UML models as they occur frequently in practice. The
designer repeatedly plays an exploration game to detect flaws or
incompleteness in the design and its specification, which are both
incorporated in the game definition. At any time the game definition
can be incremented by the modeller which allows him to react to the
discoveries made during a play and experiment with new design solutions.
Exploration games can be applied to UML in different variants. For
each variant must be specified how the UML diagrams are used to set up
the game and how the semantic variation points of UML should be
interpreted. Furthermore some parts of the game definition may not be
contained in the UML model and have to be provided separately. The
emphasis of this thesis is on game variants which make use of UML
diagrams for modelling system behaviour, especially state machines
and activity diagrams.
A prototypical implementation demonstrates how the concepts developed
in this thesis can be put into practice. The tool supports the user in
defining, playing and incrementing a game. Moreover it can compute
winning strategies for the players and may act as opponent of the
modeller. As example a game variant based on UML state machines has
been implemented. The architecture that has been chosen for the tool
leaves room for extension by additional game variants and alternative
algorithms
A design environment for mobile applications
In this paper we show how high-level UML models of mobile computing applications can be analysed for classical performance measures such as throughput. The approach proceeds by compiling the UML model into a representation in the formally-defined modelling language of PEPA nets. The compilation process and subsequent performance analysis based on numerical solution of a Continuous-Time Markov Chain is supported by a software tool, the Choreogra-pher design platform. Choreographer interoperates with popular UML tools by reading and writing UML models in the XML Metadata Interchange format (XMI).
A design environment for mobile applications
In this paper we show how high-level UML models of mobile computing applications can be analysed for classical performance measures such as throughput. The approach proceeds by compiling the UML model into a representation in the formally-defined modelling language of PEPA nets. The compilation process and subsequent performance analysis based on numerical solution of a Continuous-Time Markov Chain is supported by a software tool, the Choreographer design platform. Choreographer interoperates with popular UML tools by reading and writing UML models in the XML Metadata Interchange format (XMI).