Lutz Heuser

Distributed Systems, OSF DCE, and Beyond

This introduction paper presents basic foundations of distributed systems and applications and then shows how OSF DCE addresses the requirements imposed by distributed environments. The DCE architecture is illustrated, the basic functionality of the DCE components is explained, and the DCE RPC as the major base for client/server applications is presented in closer detail.

DOCASE: a methodic approach to distributed programming

Distributed object-oriented programming languages have proved to be superior to other known approaches for the development of complex distributed applications. Most of these languages support location-independent method invocation and object migration. Together with the fine granularity of objects, these features allow distribution-transparent modeling and programming. However, large object-oriented applications tend to exhibit huge numbers of objects and intertwine several operational software aspects for which a more methodic approach is required. The DOCASE project (Distribution and Objects in CASE) was established to identify fundamental elements of such a method approach

Using the Object Paradigm for Distributed Application Development

During the last decade, significant progress has been achieved in the area of distributed systems. At the same time, the need for distributed applications has increased heavily. A large number of distributed programming languages to support those kinds of applications is now available. Most of these approaches, however, still fail in providing appropriate levels of distribution abstraction and in supporting the software design stage. The object paradigm with extensions towards distributed systems is a promising base to overcome these shortcomings.

A software engineering environment for distributed applications

Abstract With the recent development of powerful workstations integrated in local area networks, the need for distributed applications has increased significantly. This way, formerly autonomous applications of areas like computer integrated manufacturing or office automation can be integrated to cooperating entities. However, the development of these kinds of applications is still not well supported. The paper describes an object-oriented software engineering approach for distributed applications. The approach is centered around a wide-spectrum design language used as a common base for a set of workbenches. The associated tools are focusing on problems related to distribution and complexity of applications. Life-cycle spanning development support shall be provided by the environment.

Development of distributed and client/server object-oriented applications (panel): industrial solutions

The panel will discuss emerging “industrial” solutions that help programmers to develop distributed and client/server applications based on objects supporting so-called openness and heterogeneity. The goal of the panel is to help answer the question whether there can be one single solution or whether various (integrated) approaches are needed. The panel will also compare industrial solutions such as COM, DSOM, CORBA and OODCE with results that came out of academia. Finally, a set of questions will be answered by each panelist according to the approach he will propose.

Smart Traffic Flow

ZusammenfassungFortschrittliche Informations- und Kommunikationstechnik gilt als ein wesentliches Hilfsmittel, mit dem Städte den zunehmenden Herausforderungen der Urbanisierung begegnen können. Dabei geht es vor allem um die Integration von Systemen und Daten aus verschiedenen Domänen wie Energie, Verkehr, Umwelt etc. Der Artikel zeigt, wie eine urbane Informations- und Service-Plattform Daten aus unterschiedlichen, ursprünglich isolierten, städtischen Datenquellen integrieren und auswerten kann sowie für Dienste in Realzeit nutzen kann. Auf dieser Datenbasis können Städte und Dritte einerseits Dienste realisieren für die Optimierung interner Prozesse, andererseits auch Open Data Services für Bürger und Unternehmen oder sonstige Organisationen anbieten. Der Schwerpunkt der Betrachtung liegt mit Smart Traffic Flow auf der Domäne des städtischen Verkehrs. Am Beispiel der Stadt Darmstadt wird gezeigt, wie sich eine solche Plattform und geeignete Dienste für intelligente Verkehrsflussgestaltung nutzen lassen. Mithilfe eines Demonstrators wird außerdem verdeutlicht, wie im Bereich Verkehr künftig die individuelle Gestaltung von Mehrwertdienstbündeln durch den Benutzer entsprechend seiner Bedürfnisse realisiert werden kann.

How to Support the Development of Distributed Object Oriented Applications

The need for distributed applications is growing dramatically due to the fact that state-of-the-art software cannot keep pace with the capabilities of “networked workstations”. New techniques are investigated to design distributed applications in a well-structured, object oriented way. In addition transparency in object oriented approaches hides underlying communication protocols. However, supporting the development of such applications is lacking in appropriate techniques and methodologies. The DOCASE project proposes a methodology, which enables the programmer to develop his application starting with the design phase, and accompanies him through the subsequent stages of the software life cycle.

Digitale Mehrwertdienste in Smart Cities am Beispiel Verkehr

Dieses Kapitel skizziert nach einer Einfuhrung zunachst die Architektur einer offenen urbanen Informations- und Service-Plattform, welche Daten aus Domanen wie Energie, Verkehr, Umwelt etc. aus stadtischen und privatwirtschaftlichen Quellen integrieren, auswerten und fur Dienste nutzbar machen kann. Anschliesend liegt der Betrachtungsschwerpunkt mit Smart Mobility Services auf der Domane des stadtischen Verkehrs. Ausgewahlte Beispiele fur solche Dienste in mehreren Stadten illustrieren die Wirkungsweise in Verbindung mit der Plattform und die Beitrage, die diese Infrastruktur liefern kann, um Stadte „smart“ zu machen.

Facility Management by Means of Subject Oriented Cross Organizational Business Process Management

The task of facility management (FM) enjoys increasing popularity nowadays. There are to main reasons for this[1]: Buildings and land form one of the largest asset item in the balance sheet of companies which can be reduced by FM. On the other hand, the environmental conditions for employees are supposed to be improved continuously. A good working environment increases the productivity of the employees and FM can support this task. Current approaches for managing building services have many disadvantages: The services are quit strongly coupled or even not compos able at all, the support for cross organizational service composition is often weak and they lack of an overall concept to integrate building services into business processes. Moreover, the case studies cover rather high level concepts instead of concrete examples. To overcome these drawbacks, we introduce an new approach that enables FM by means of cross organizational Business Process Management and explain the way BPM is combined with service composition. As BPM foundation we use the Subject Oriented Business Process Management (S-BPM) paradigm. Furthermore a detailed user study of a cross organizational service composition is given.