Peter Manhart

First-class variability modeling in Matlab/Simulink

Modern cars exist in an vast number of variants. Thus, variability has to be dealt with in all phases of the development process, in particular during model-based development of software-intensive functionality using Matlab/Simulink. Currently, variability is often encoded within a functional model leading to so called 150%-models which easily become very complex and do not scale for larger product lines. To counter these problems, we propose a modular variability modeling approach for Matlab/Simulink based on the concept of delta modeling [8, 9, 24]. A functional variant is described by a delta encapsulating a set of modifications. A sequence of deltas can be applied to a core product to derive the desired variant. We present a prototypical implementation, which is integrated into Matlab/Simulink and offers graphical editing of delta models.

A generic system for Web-based group interaction

The WWW has become the most important information system. But the demand of Web-based human interaction in a lot of situations, scenarios and applications e.g. electronic commerce and tele-learning, is still unsupported. Founding on a scenario-based requirements analysis we developed concepts, a client server architecture and a prototype of a basic group interaction system (gia-system). It currently supports user and group awareness, and communication facilities such as that based either on dynamic group building or static acquaintance groups, and cooperative navigation. The gia-system, already evaluated within an electronic market place, is currently enhanced in two ways: First we investigate in more generic group building mechanisms than the existing location and acquaintance based one. Second we work on cooperation support for semi-structured activities.

Behavioral compatibility of simulink models for product line maintenance and evolution

Embedded software systems, e.g. automotive, robotic or automation systems are highly configurable and consist of many software components being available in different variants and versions. To identify the degree of reusability between these different occurrences of a component, it is necessary to determine the functional backward and forward compatibility between them. Based on this information it is possible to identify in which system context a component can be replaced safely by another version, e.g. exchanging an older component, or variant, e.g. introducing new features, to achieve the same functionality. This paper presents a model checking approach to determine behavioral compatibility of Simulink models, obtained from different component variants or during evolution. A prototype for automated compatibility checking demonstrates its feasibility. In addition implemented optimizations make the analysis more efficient, when the compared variants or versions are structurally similar. A case study on a driver assistance system provided by Daimler AG shows the effectiveness of the approach to automatically compare Simulink components.

A classification of modeling variability in simulink

Todays cars are characterized by many functional variants. There are many reasons for the underlying variability, from the adaptation to diverse markets to different technical aspects, which are based on a cross-platform reuse of software functions. Inevitably, this variability is reflected in the model-based automotive software development. A modeling language, which is widely used for modeling embedded software in the automotive industry, is Matlab/Simulink. There are concepts facing the high demand for a systematic handling of variability in Simulink-models. However, not every concept is suitable for every automotive application. In order to present a classification of concepts for modeling variability in Simulink, this paper first has to determine the relevant use cases for variant handling in model-based automotive software development. Existing concepts for modeling variability in Simulink will then be presented before being classified in relation to the previously determined use cases.

A system architecture for the extension of structured information spaces by coordinated CSCW services

The World Wide Web is an emerging platform for information systems; however established system architectures for web systems focus mainly on the creation and storage of consistent hypermedia information structures and on the efficient distribution of the resulting documents. The interaction between the information users is seldom supported. As many application scenarios profit greatly from human interaction, the paper presents a platform- and application-independent generic system architecture designed to extend existing web-based information systems by coordinated services for human interaction. One prototype implementation of the architecture supports user awareness and human interaction on corporate web sites.

Web-basiertes, kooperatives Lernen auf Basis dynamischer Gruppenbildung

Hohe Innovationszyklen, wechselnde Rahmenbedingungen und laufend neue Anforderungen, erfordern standiges Lernen, von jedem Einzelnen, Gruppen und auch von Organisationen. Daraus resultiert ein wachsender Bedarf an geeigneten lernunterstutzenden Systemen. Dieser Beitrag beschreibt ein Web-basiertes System zur Unterstutzung kooperativen Lernens in einer anpasbaren, offenen Umgebung. Im Gegensatz zu vielen vorhandenen, traditionellen Systemen konzentriert sich dieser Ansatz auf gruppenorientiertes Lernen, im besonderen auf die Aspekte (1) Wahrnehmung anderer Lernenden, (2) dynamische Gruppenbildung, in Abhangigkeit von den Interessen und Wunschen des Lernenden und (3) Unterstutzung der Interaktion.