Contributions published at Department of Informatics (Burkhard Stiller)

Effiziente, konstruktive und zielgerichtete kooperative Zusammenarbeit spielt in einer Zeit immer schnellerer Entwicklungszyklen die entscheidende Rolle im Kampf um Marktvorteile. Hier, wie auch in vielen anderen Arbeits- und Lebensbereichen, eröffnet der Einsatz von Informationstechnologie neue, faszinierende Perspektiven, die zu entscheidenden Veränderungen in der menschlichen Zusammenarbeit in Unternehmen und im Privatbereich geführt haben und noch führen werden. Dieses Buch liefert einen umfassenden, kompetenten und auch für den Nicht-Fachmann verständlichen Einblick in die Grundlagen, Methoden und Konzepte, die Werkzeuge und Anwendungen und die Potenziale, Wirkungen und Perspektiven computerunterstützter kooperativer Zusammenarbeit. Das von international anerkannten Autoren geschriebene Buch eignet sich als einführendes Lehrbuch für Studierende an Universitäten und FHs und als Handbuch für Entwickler und Praktiker.

null

null

null

This thesis presents a methodology extension named MeTHOOD (Measures, Transformation Rules and Heuristics for Object-Oriented Design) that supports the design of objectbases. MeTHOOD integrates measures describing the design objectives, heuristics showing design alternatives and transformation rules that enable design transformations. MeTHOOD makes design knowledge for conceptual objectbase schemas (conceptual object-oriented class schemas) more tangible. Although a large amount of this important knowledge is available in the literature, it is hardly usable for designers because it is very scattered, on different levels of abstraction and not integrated. Thus, the objective of this thesis is to enable a design process for efficient and continuous quality inspection and improvement of conceptual class schemas by efficiently providing design knowledge. The core of MeTHOOD is a catalogue of integrated design knowledge consisting of already existing as well as new object-oriented design heuristics, transformation rules and measures. This knowledge is the base for the iterative MeTHOOD design process. It consists of the main activities measurement, design inspection and design transformation. Using measurement, important properties of the schema are assessed. Based on the measured values and the heuristics, it is possible to inspect the schema systematically. The result of the inspection is a set of potential design flaws. The actual design flaws (identified by the designer) can then be eliminated using schema transformation. The result is a new schema that can be compared to the old one using new and old measures. These activities are supported by concrete measures and heuristics acting as a driver for transformations. The process is supported by a design support system called MEx (MeTHOOD Expert). MEx provides semi-automatic design monitoring, heuristic checking and design transformation using the design knowledge of the MeTHOOD catalogue.

null

With on-line ordering and electronic commerce, the Internet moves from a passive information role to an active role as a computational medium for supporting the execution of business processes. This study is motivated by this trend and it investigates agent oriented and role based business process management for computational media. In this thesis, a conceptual framework for agent oriented and role based business process management has been established. We view a business process as a collection of autonomous, problem solving agents which interact with other agents when they have interdependencies. In particular, we model a process as a set of roles and a set of conversations among roles. A protocol defines a set of rules governing role-interaction in a conversation. We define roles in term of goals, qualifications, obligations, permissions, and relations to other roles, etc. Roles are assigned to agents based on the evaluation of qualifications and agents' capabilities. Once a role is assigned to an agent, the agent becomes the subject of the rights and duties specified by that role. Coordination of processes is achieved by communication among agents. Moreover, the main constructs of the role-based process description language have been identified. The role based approach for developing agent oriented business process management systems has been developed. An agent is an active entity whose state is viewed as consisting of mental components such as beliefs, capabilities, choices, and commitments. We have shown our role model matches with the agent's mental components perfectly. We supplemented our conceptual framework with practical dimension which leads us to build the agent enhanced peer review process management system. In the case study, we have presented the standard peer review process, discussed the administrative peer review process and ad hoc peer review process, and analyzed the Internet peer review process. Thereafter, the agent enhanced peer review process has been developed. We have modeled the process with Role Activity Diagrams and Finite States Machines. Then obligations of roles and protocol rules of conversations have been derived from them. Furthermore, a general set of messages for the agent enhanced peer review process has been defined and a deontic specification of the protocols has been shown. Finally, the peer review process management system is designed as a Multi-agent system. The work has both practical and theoretical implications. The result contributes to the study of Computational Media, Multi-agent systems, and Business Process Management as well. From the work, we have found that agent oriented processes take a distributed, and thus a more robust, flexible, and scaleable approach to business process management. Business processes and the Internet are more effective in combination than alone. Electronic Commerce and many other ""Virtual organization"" applications can be easily imagined.

Tremendous changes have been taking place in information technology for a few decades. Due to the rapid evolution in this area, the demand for innovation in this area is much higher than elsewhere. This requires large efforts of companies to respond quickly to market conditions in order to organize work and conduct business more efficiently. In particular, companies have to reengineer existing information systems in order to take benefit of new key technologies like WWW or E-commerce. A typical scenario in many companies when applying a reengineering process is that on the one hand, a large body of data is captured in relational (or even hierarchical or network) databases, and on the other hand new object-oriented applications have to be developed. Thereby, a new object model is constructed which represents the current state of the companies business processes. However, the new object model and the existing relational database's model usually do not go well together. In other words, a large semantic gap between both models must be bridged. The approach proposed in this thesis is database migration. Basically, this approach comprises two tasks. In the first task, the relational database schema is reengineered. The schema is transformed into a well-designed and intuitively understandable object-oriented schema, which the new applications can adapt. Afterwards, the data are (automatically) migrated into an object-oriented DBMS. Existing approaches for migration do not exploit the full potential of the object-oriented paradigm so that the resulting object-oriented schema still ""looks rather relational"" and retains the drawbacks and weaknesses of the relational schema. Therefore, one of the goals of this approach is to support schema transformation into an adequate object-oriented schema as obtained by forward engineering, rigorously using an object-oriented design method. In the first part of the thesis, the fundamental differences between relational and object-oriented database design are discussed. The results of this part are classified into four categories: specification of object-oriented behaviour, navigational vs. set-oriented data access, object life cycles, and deficiencies of relational database schemas. Each category represents a specific aspect in which relational database design differs principally from object-oriented design. For the implementation of the database migration process an intermediate data model (SOT, Semi Object Types) is proposed which allows to define both, schema transformation and data migration. This data model contains all object-oriented modeling constructs and supports flexible schema transformation. Furthermore, an algebra is proposed for a formal definition of the data migration process. The schema transformation process is subdivided into three sequential phases. In the first phase, the relational schema is transformed (automatically) into an SOT schema. This initial SOT schema is then redesigned resulting in an adequate object-oriented schema. Finally, in the third phase the resulting SOT schema is (again automatically) transformed into an object-oriented schema according to the ODMG standard. The data migration process is generated automatically for each schema transformation phase. In order to implement schema transformation, the concept of the transformation rule is proposed. The transformation rules define elementary restructuring operations within the SOT model. A basic set of transformation rules has been proposed which can be extended. Finally, a prototype has been implemented as a proof of concept.

null

The classical notion of requirements quality is problematic in practice. Hence the importance of some qualities, in particular completeness and unambiguity, has to be rethought. Scenarios, the description of requirements as sequences of interactions, prove to be a key concept for writing requirements specifications that are oriented towards such a modified set of qualities. In this paper, the potential of scenarios for improving the quality of requirements is discussed. Furthermore, a concept for systematically representing both single scenarios and the structure and relationships in a set of scenarios is presented. Using an example, the positive impact of this style of representation on the quality of the requirements is demonstrated.

null

null

Immer häufiger erkennen Unternehmen das Potential interorganisatorischer Informationssysteme (IOS) zur Erschliessung neuer Geschäftsbeziehungen und innovativer Unternehmensstrategien. Das wird in der zunehmenden Nutzung des Internets für Electronic Commerce im Business-to-Business-Bereich deutlich. Thomas Gaugler entwickelt einen umfassenden, wirkungsorientierten Analyse- und Gestaltungsrahmen, der dem Informationsmanagement die systematische Planung, Entwicklung und Einführung von IOS ermöglicht. Der Autor zeigt die theoretischen Grundlagen, den aktuellen Stand und die möglichen Wirkungen eines IOS-Einsatzes auf. Darüber hinaus präsentiert er konkrete Gestaltungsoptionen, bei denen verschiedene Perspektiven und Zielgruppen unterschieden werden.

In the past, most collaboration support systems have focused on either automating fixed work processes or simply supporting communication in ad-hoc processes. This results in systems that are usually inflexible and difficult to change or that provide no specific support to help users decide what to do next. This paper describes a new kind of tool that bridges the gap between these two approaches by flexibly supporting processes at many points along the spectrum: from highly specified to highly unspecified. The development of this approach was strongly based on social science theory about collaborative work.

null

null