UML is the rst OO modeling language with a useful modularization and information hiding concept. It supports nesting, import, and reenement of so-called packages. This paper translates UML's informal package deenition into predicate logic formulas and solves some open problems concerning the visibility of exported and imported modeling elements. Furthermore, the formulas will be transformed int...

The unified modeling language (UML) developed under the coordination of the Object Management Group (OMG) is one of the most important standards for the specification and design of object oriented systems. This standard is currently tuned for real time applications in the form of a new proposal, UML for Real-Time (UML-RT), by Rational Software Corporation and ObjecTime Limited. Because of the i...

The Unified Modeling Language is extensible, and so can be regarded as a family of languages. Implicitly or explicitly, any particular UML model should be accompanied by a definition of the particular UML family member used for the model. The definition should cover syntactic and semantic issues. This paper proposes a mechanism for associating models with such definitions. Any particular defini...

Current equation-based modeling languages are often confronted with tasks that partly diverge from the original intended application area. This results out of an increasing diversity of modeling aspects. This paper briefly describes the needs and the current handling of multi-aspect modeling in different modeling languages with a strong emphasis on Modelica. Furthermore a small number of langua...

The key to systematic development of complex, reactive systems is to have a thorough understanding of the services the system provides. A service, in our view, is defined by the interplay among components required to establish a certain result. Services shift attention from the details of individual components to a global view of the system. We give a formal definition for the notion of service...

This paper presents an augmented framework for analyzing Safety Critical Systems (SCSs) formally. Due to high risk of failure, development process of SCSs is required more attention. Model driven approaches are the one of ways to develop SCSs for accomplishing critical and complex function what SCSs are supposed to do. Two model driven approaches: Unified Modeling Language (UML) and Formal Meth...

This paper presents an architecture for model-based verification and testing using a profile of the Unified Modeling Language (UML). Class, object, and state diagrams are used to define essential models: descriptions that are relatively complete. Object and state diagrams are used to introduce test directives. Models written in this profile may be compiled into a tool language: the Intermediate...

The Unified Modeling Language (UML) is accepted today as an important standard for developing software. UML tools however provide little support for validating and checking models in early development phases. There is also no substantial support for the Object Constraint Language (OCL). We present an approach for the validation of UML models and OCL constraints based on animation and certificat...