Marko Boger

Electronic contracting with COSMOS-how to establish, negotiate and execute electronic contracts on the Internet

Today, the Internet gains more and more attraction even for small companies to contact business partners and to automate cooperation between each other. However, the smaller the company the higher the relative setup costs that are required if the complete process of a commercial transaction is to be supported. We propose COSMOS as an Internet-based electronic contracting service that facilitates commercial partners with offer catalogues, a brokerage service, contract negotiation and signing as well as contract execution. The COSMOS architecture supports these functions in an integrated, unified way. The design and execution of contracts integrates patterns from the CORBA Joint Business Object Facility.

SUPPORTING ELECTRONIC COMMERCE TRANSACTIONS WITH CONTRACTING SERVICES

Based on the specific characteristics and requirements for an adequate electronic commerce system support, this article gives an overview of the respective distributed systems technologies which are available for open and heterogeneous electronic commerce applications. Abstracting from basic communication mechanisms such as (transactionally secure) remote procedure calls and remote database access mechanisms, this includes service trading and brokerage functions as well as security aspects including such as notary and non-repudiation functions. Further important elements of a system infrastructure for electronic commerce applications are: Common middleware infrastructures, componentware techniques, distributed and mobile agent technologies etc. As electronic transactions enter the phase of performance, increasingly new and important functions are required. Among these are: Negotiation protocols to support both the settlement and fulfillment of electronic contracts as well as ad-hoc workflow management support for compound and distributed services in electronic commerce applications. In addition to an overview of the state of the art of the respective technology, the article briefly presents some related projects conducted by the authors jointly with international partners in order to realize some of the important new functions of a system infrastructure for open distributed electronic commerce applications.

Diagram Interchange for UML

XMI is a standardized mechanism for exchanging UML models. However, this mechanism does not sufficiently fulfill the goal of a model interchange: it doesno t include the exchange of diagram information. XMI asde fined for UML 1.x is only capable of transporting information on the elementsin an UML model but not information as to how these elements are represented and laid out in diagrams.This paper proposes an extension to the UML metamodel to represent diagram information in a graph-oriented manner. The approach presented isab le to fix the deficiency for UML 1.x and solve the problem for UML 2.0. The approach wash anded in for standardization to the OMG in response to the Diagram Interchange RFP.

Refactoring Browser for UML

Refactoring is a corner stone in a number of agile processes like Extreme Programming (XP). Tools for an automatic support are beginning to appear, usually referred to as refactoring browsers. Most of these are extensions to editors or IDEs and operate on code. This paper discusses how the idea of refactoring can be extended to UML models and presents a refactoring browser integrated in a UML modelling tool. Refactorings for the static architecture as well as for the dynamic behaviour are presented.

Modeling dynamic software components in UML

UML provides modeling support for static software components through hierarchical packages. We describe a small extension of UML for modeling dynamic software components which can be instantiated at runtime, customized, made persistent, migrated and be aggregated to larger components. For example, this extension can be used to describe systems built with JavaBeans, ActiveX-Controls, Voyager Agents or CORBA Objects by Value. With our extension, the lifecycle of a dynamic software component can be expressed in terms of UML. We can not only describe a system at design time, but also monitor its runtime behaviour. A re-engineering tool is presented that exploits our UML extension for a high-level visualization of the interaction between dynamic components in an object-oriented system.

Generating Code from UML with Velocity Templates

The value of automatedco de generation is increasingly recognized, and the application model becomes the central artefact in the software development process. Model-driven development requires a rapida ndfle xible code generation mechanism. This paper discusses code generation based on templates that actively access UML model information to fill an implementation skeleton. Different templates result in different generated code, providing a highly flexible generation mechanism. Along with a discussion on the potential of such a code generation, an existing framework for code generation with templates is presented.

Dejay: unifying concurrency and distribution to achieve a distributed Java

In the development of distributed programs, two different concepts have to be considered, each being quite complex even on its own: concurrency and distribution. For both concepts, similar problems like synchronization and communication need to be addressed, yet they are treated with completely different mechanisms. The paper presents Dejay, a programming language based on Java that unifies concurrency and distribution into the single mechanism of virtual processors. This allows a considerable simplification for the development of distributed or concurrent programs and makes the transition from a local to a distributed environment seamless.

Migrating Objects in Electronic Commerce Applications

Electronic Commerce is a field of application that is distributed by nature where different parties share information and work concurrently and cooperatively on objects, potentially distributed over a large scale network like the Internet. In such an environment client/server architectures reach the limit of their capability. Non-centralized distributed architectures with object and code migration are more suitable. This paper presents a distributed extension to Java named Dejay. Its aim is to simplify the design and development of such distributed systems. Concurrency and distribution are expressed using the same mechanism, virtual processors. These processors represent one thread of control. They contain groups of objects and manage their synchronization and migration over distributed networks. It is used as an implementation language for distributed electronic commerce applications.

Electronic Contracting im Internet1

Heute bietet das Internet nicht nur fur Groβunternehmen sondern auch fur kleine Unternehmen Moglichkeiten zur automatisierten Kooperation. Im Bereich des Bu- siness-to-Business-Commerce wurden jedoch bisher kleine Unternehmen aufgrund relativ hoher Transaktionskosten eher davon abgehalten, Handelstransaktionen uber das Internet durchzufuhren. Fur solche Anwendungsbereiche wird in diesem Beitrag das COSMOS-Projekt (Common Open Service Market fOr SMEs) und seine Architektur vorgestellt, mit deren Hilfe die Vermittlung von Transaktionspartnern, der Aushandlungsprozeβ eines Vertrages sowie das Unterzeichnen und schlieβlich die Abwicklung der vertraglich vereinbarten Leistungen durch eine verteilte Kollaborationsanwendung unterstutzt wird. Dabei basiert die COSMOS-Architektur auf einem einheitlichen Vertragsmodell und unterstutzt diese Prozesse in integrierter Form. Architektureil erfolgt der Systementwurf in Anlehnung an den CORBA Business Object Component Architecture (BOCA).

Extreme Programming and Modelling

Extreme Programming (XP:see http://www.xprogramming.com ,developed by Kent Beck and others,has recently taken the OO development world by storm. It can be seen as an antidote to over-documented,in flexible development pro- cesses;by taking certain good practices (testing,iteration and code reviewing, for example)to extremes,its adherents claim to achieve better results at lower cost.