Designing precise and flexible graphical modelling languages for software development

Model-driven approaches to software development involve building computerized models of software and the environment in which it is intended to operate. This thesis offers a selection of the author’s work over the last three decades that addresses the design of precise and flexible graphical modelling languages for use in model-driven software development. The primary contributions of this work are: • Syntropy: the first published object-oriented analysis and design (OOAD) method to fully integrate formal and graphical modelling techniques. • The creation of the Object Constraint Language (OCL) and its integration into the Unified Modeling Language (UML) specification. • The identification of requirements and mechanisms for increasing the flexibility of the UML specification. • The design and implementation of tools for implementing graphical Domain Specific Languages (DSLs). The starting point was the author’s experience with formal specification techniques contrasted with the lack of precision of published object-oriented analysis and design methods. This led to a desire to fully integrate these two topics – formal specification and object-orientation - into a coherent discipline. The Syntropy approach, created in 1994 by this author and John Daniels, was the first published complete attempt to do this. Much of the author’s subsequent published work concerns the Unified Modeling Language (UML). UML represented a welcome unification of earlier OOAD approaches, but suffered badly from inflexibility and lack of precision. A significant part of the work included in this thesis addresses the drawbacks of the UML and proposes improvements to the precision of its definition, including through the invention of Object Constraint Language (OCL) and its incorporation into the UML specification, and the consideration of UML as source material for the definition of Domain Specific Languages (DSLs). Several of the author’s published works in this thesis concern mechanisms for the creation of DSLs, both within a UML framework and separately

Report on the Aachen OCL meeting

As a continuation of the OCL workshop during the MODELS 2013 conference in October 2013, a number of OCL experts decided to meet in November 2013 in Aachen for two days to discuss possible short term improvements of OCL for an upcoming OMG meeting and to envision possible future long-term developments of the language. This paper is a sort of "minutes of the meeting" and intended to quickly inform the OCL community about the discussion topics

Adding Graph Transformation Concepts to UML's Constraint Language OCL

AbstractThe Object Constraint Language OCL is an integral part of UML, the Unified Modeling Language standard. It has been added to UML as a logic-based sublanguage for the definition of class invariants and pre-/postconditions of operations. OCL is rather similar to a subset of the graph transformation language PROGRES, the so-called path expressions. These path expressions are used for similar purposes as OCL. In contrast to OCL, path expressions support functional abstraction and offer additional operators for conditional iteration and transitive closure. Furthermore, PROGRES possesses a visual query sublanguage and is equipped with a precise semantics definition. Based on our experiences with the development of PROGRES a number of modifications and extensions of OCL are suggested as recommendations for its forthcoming version 2.0

UML-F: A Modeling Language for Object-Oriented Frameworks

The paper presents the essential features of a new member of the UML language family that supports working with object-oriented frameworks. This UML extension, called UML-F, allows the explicit representation of framework variation points. The paper discusses some of the relevant aspects of UML-F, which is based on standard UML extension mechanisms. A case study shows how it can be used to assist framework development. A discussion of additional tools for automating framework implementation and instantiation rounds out the paper.Comment: 22 pages, 10 figure

Tрехзначные логики Клини и Трехэлементные цепи

Рассмотрена сильная и слабая трехзначные логики Клини. Показано возникновение сильной логики из обычной булевой логики путем применения общезначимой конструкции распространения операций с элементов на множества элементов в терминах полного образа. Проиллюстрировано компактное задание операций обоих логик Клини трехэлементными цепями

Виникнення та інтерпретація тризначних логік Кліні

Розглянуто сильну та слабку тризначні логіки Кліні. Показано виникнення сильної логіки зі звичайної булевої логіки шляхом застосування загальнозначущої конструкції розповсюдження операцій з елементів на множини елементів у термінах повного образу. Проілюстровано компактне задання операцій логіки Кліні трьохелементними ланцюгами.Strong and weak three-valued Kleene logics are considered. The origin of strong logic from ordinary Boolean logic by application of generally valid construction of extension operations from elements on the sets of elements in terms of full image is shown. The compact representation of logic Kleene operations by the three-element chains is illustrated

Semantics of OCL specified with QVT

The Object Constraint Language (OCL) has been for many years formalized both in its syntax and semantics in the language standard. While the official definition of OCL's syntax is already widely accepted and strictly supported by most OCL tools, there is no such agreement on OCL's semantics, yet. In this paper, we propose an approach based on metamodeling and model transformations for formalizing the semantics of OCL. Similarly to OCL's official semantics, our semantics formalizes the semantic domain of OCL, i.e. the possible values to which OCL expressions can evaluate, by a metamodel. Contrary to OCL's official semantics, the evaluation of OCL expressions is formalized in our approach by model transformations written in QVT. Thanks to the chosen format, our semantics definition for OCL can be automatically transformed into a tool, which evaluates OCL expressions in a given context. Our work on the formalization of OCL's semantics resulted also in the identification and better understanding of important semantic concepts, on which OCL relies. These insights are of great help when OCL has to be tailored as a constraint language of a given DSL. We show on an example, how the semantics of OCL has to be redefined in order to become a constraint language in a database domai

A conceptual model of service exchange in service-dominant logic

The service system is the basic abstraction of Service Science. This paper proposes the Resource-Service-System model as a conceptual model of service systems interacting in service exchanges, assuming a service-dominant logic economic worldview. The paper explains how the model was developed starting from the Resource-Event-Agent business model ontology, taking into account insights gained from studying Service Science literature and existing service ontologies. The paper also explains how different model views can contribute to study various aspects of service systems and exchanges