Luuk Groenewegen

A methodology for specifying and analyzing consistency of object-oriented behavioral models

Object-oriented modeling favors the modeling of object behavior from different viewpoints and the successive refinement of behavioral models in the development process. This gives rise to consistency problems of behavioral models. The absence of a formal semantics for UML models and the numerous possibilities of employing behavioral models within the development process lead to the rise of a number of different consistency notions. In this paper, we discuss the issue of consistency of behavioral models in the UML and present a general methodology how consistency problems can be dealt with. According to the methodology, those aspects of the models relevant to the consistency are mapped to a semantic domain in which precise consistency tests can be formulated. The choice of the semantic domain and the definition of consistency conditions can be used to construct different consistency notions. We show the applicability of our methodology by giving an example of a concrete consistency problem of concurrent object-oriented models.

Consistency-Preserving Model Evolution through Transformations

With model-based development being on the verge of becoming an industrial standard, the topic of research of statically checking the consistency of a model made up of several submodels has already received increasing attention. The evolution of models within software engineering requires support for incremental consistency analysis techniques of a new version of the model after evolution, thereby avoiding a complete reiteration of all consistency tests.In this paper, we discuss the problem of preserving consistency within model-based evolution focusing on UML-RT models. We introduce the concept of a model transformation rule that captures an evolution step. Composition of several evolution steps leads to a complex evolution of a model. For each evolution step, we study the effects on the consistency of the overall model and provide localized consistency checks for those parts of the model that have changed. For a complex evolution of a model, consistency can then be established by incrementally performing those localized consistency checks associated to the transformation rules applied within the evolution.

Object-oriented modeling: a roadmap

Object-oriented modeling has become the de-facto standard in the early phases of a software development process during the last decade. The current state-of-the-art is dominated by the existence of the Unified Modeling Language (UML), the development of which has been initiated and pushed by industry. This paper presents a list of requirements for an ideal object-oriented modeling language and compares it with the achievements of UML and other object-oriented modeling approaches. This forms the base for the discussion of a roadmap for object-oriented modeling, which is structured according to a classification scheme of six different themes, which are language-, modelor process-related, respectively.

Delegation modeling with paradigm

Within one model, behavioural consistency of its constituents is often problematic. Within UML such horizontal behavioural consistency between the objects of a concrete model, is particularly needed in the context of dynamic patterns. Here, we investigate delegation, which is fundamental to patterns that separate the locality of receiving a request, and one or more localities actually handling it. We specify delegation by means of the coordination language Paradigm. In particular, we present some variants of delegation in the context of a broker pattern and clarify how the Paradigm notions are the basis for understanding a solution as well as for adapting it to deal with other dynamic features.

Integration of information systems: assessing its quality

Due to organizational and technological changes the need for integrating information systems within healthcare institutions, has increased enormously. Although the technical means for systems integration have definitely matured, integration methodologies are still in their infancy. Two important questions regarding systems integration are hardly ever addressed in a systematic way: how to derive integration requirements, and how to check whether the requirements are met in a given integrated system. These two questions must be answered if we want to assess or improve the quality of integration of a given set of systems. In this article we present a nine-step method for deriving integration requirements from a business process model, and we assess the quality of integration of a given integrated system against these requirements. The method is demonstrated by elaborating two case studies from the health care domain.

Constructing an enterprise viewpoint: evaluation of four business modelling techniques

Business process modelling is presented as an important first step in the process of designing a distributed system by integrating pre-existing components. The elements describing a business process are derived from the ODP-enterprise viewpoint language. One of the viewpoints distinguished in the Open Distributed Processing standard is the enterprise viewpoint. This viewpoint describes the organizational context in which the distributed system to be constructed will be used. In this paper we will review four business modelling techniques and their suitability for expressing the enterprise viewpoint is evaluated.

Towards team-automata-driven object-oriented collaborative work

The paper studies and compares two different approaches to model communication and cooperation. The approaches are team automata, a well-defined variant of communicating automata, and state-charts, heavily used in object-oriented modelling methods. The comparison yields interesting insights for modelling communication and cooperation. In particular, the differences between action-based, synchronous and state-based, asynchronous communication are elucidated.

Industrial maintenance modelled in SOCCA: an experience report

A large industrial process, software maintenance, has been modelled by using the process modelling language SOCCA. The paper reports about the experiences with this trial. In particular, feasibility, expressiveness, quality and the overall benefits of a formal SOCCA model are discussed and compared to the formerly existing informal process description. In order to illustrate the results, a well chosen process model fragment from the larger model is outlined in detail. It addresses in particular the human-intensive cooperation within the process and shows the seamless combination of technical components and human agent components in the SOCCA model. The main conclusions from this trial are that formal SOCCA models are suited to model realistic industrial processes and that due to an intrinsic modular structure of a SOCCA model, even huge models remain reasonably readable and understandable.

Object-oriented specification of coordinated collaboration

Object-oriented specification mechanisms have become famous for modelling structure and behaviour together in terms of autonomous objects communicating via message passing. However, whereas most object-oriented specification methods are strong in modelling the local behaviour of single objects, they fall short on modelling the coordinated behaviour and collaboration of several objects together. The aim of this paper is to contribute to fill this gap. The paper reports on concepts, language constructs, and experiences with three collaboration formalisms in the area of object-oriented specifications.

Specifications of Coordinated Behaviour by SOCCA

The software process situations to be modelled usually exhibit a great diversity and complexity, as data, local behaviour as well as coordination of behaviour of human and non-human agents have to be modelled on a fine-grained level. Unfortunately no existing specification formalism seems to be sufficiently suitable. To this aim the paper proposes a specification formalism, which combines the best fitting (parts of) different formalisms, in order to attain a satisfactory specification. The combination discussed in this paper is SOCCA (Specifications Of Coordinated and Cooperative Activities), composed of Extended Entity-Relationship (EER) based object-oriented modelling for the data perspective, state transition diagrams for the local behaviour perspective, and PARADIGM for the coordination of behaviour perspective.