Jürgen Mangler

Towards Compliance of Cross-Organizational Processes and Their Changes

Businesses require the ability to rapidly implement new processes and to quickly adapt existing ones to environmental changes including the optimization of their interactions with partners and customers. However, changes of either intra- or cross-organizational processes must not be done in an uncontrolled manner. In particular, processes are increasingly subject to compliance rules that usually stem from security constraints, corporate guidelines, standards, and laws. These compliance rules have to be considered when modeling business processes and changing existing ones. While change and compliance have been extensively discussed for intra-organizational business processes, albeit only in an isolated manner, their combination in the context of cross-organizational processes remains an open issue. In this paper, we discuss requirements and challenges to be tackled in order to ensure that changes of cross-organizational business processes preserve compliance with imposed regulations, standards and laws.

Building a modular service oriented workflow engine

Current workflow engines, often based on WS-BPEL, are monolithic programs to orchestrate a business process or take part in choreography between partners. They cover aspects like the execution of the workflow description derived from the business process, the communication with external services, and the handling of errors. Both, the communication with services as well as basic error handling are covered by static and internal APIs [S. Modafferi, E. Mussi, and B. Pernici (2006)], and thus provide only simple strictly internal means of interaction with running workflows. Introducing new repair algorithms or self-healing behavior require detailed monitoring and modification of all aspects of a workflow execution thus requiring a modularization of the workflow engine itself. In this paper we will present a modular and service oriented workflow engine. Modularity and service-orientedness are realized by integrating a workflow execution engine with means of logging, repair and possibility to invoke external services through simple Web-based APIs.

Towards Living Inter-organizational Processes

Business Process Management (BPM) has gained significant adoption in practice for enabling organizations to increase their effectiveness, efficiency, and flexibility. This broad adoption has not only been fostered by a rich and well-established theory to model, analyze, simulate, and enact business processes, but also by internationally accepted standards and mature technologies. Caused by the ever increasing speed and volatility of markets and the dynamics of new technologies, such as cloud infrastructures and mobile communications, we face a new generation of business processes, which we refer to as living inter-organizational processes. Such processes are not in control of one single organization, instead, they are enacted by multiple organizations, where no participating party possesses full control over the entire process. Such processes often involve a high number of actors that might even be unknown in advance. These actors require various degrees in participation, they are acting in heterogeneous environments. Moreover, such processes are often weakly structured or designed in an ad-hoc manner, and have to be continuously subject to evolution. Unfortunately, existing theories, methodologies, and technologies cannot cope with this challenging combination of aspects, which all have to be considered when dealing with living inter-organizational processes. The state of the art typically addresses singular aspects in isolation. However, a holistic approach to these challenges bears a tremendous potential. This paper aims to contribute towards a holistic approach to living inter-organizational processes. To this end, we describe different perspectives on inter-organizational processes and identify challenges for making them living processes.

Rule-Based Synchronization of Process Activities

Synchronization of running process instances has been identified as major challenge in literature and practice. Although process instances are, for example, often required to share resources such as printers or centrifuges, the necessary instance synchronization is not supported by most process engines. While existing (scarcely supported) patterns deal with the intra-process synchronization of activities, a model for a more generic synchronization mechanism is still missing. The contribution of this paper is two-fold. (1) We introduce a generic model to describe the state transitions of process instances at runtime, and based on this model (2) define a subscription based event / voting mechanism that enables arbitrary synchronization within and between running instances. In order to demonstrate the validity of our approach, we will conduct an extensive evaluation against existing synchronization patterns, as well as describe a generic rule engine prototype that implements the presented approach.

Online versus Face-to-Face Peer Team Reviews

Peer-reviewing is gaining importance as didactic technique in computer science courses. Through reviewing their peers, students develop evaluation skills, increase their reflection ability, and develop awareness of their own works quality. This paper presents an experimental study exploring communication and collaboration aspects of the peer-reviewing task. In particular, the study analyzes differences between the face-to-face and the online setting. Both settings were implemented and investigated with respect to communication and collaboration in and among teams as well as workload distribution. The results show that students highly appreciated many aspects of the online reviewing tool but found themselves constrained by the lack of discussion, which they experienced and valued in the face-to-face process. The paper discusses further results regarding team communication and collaboration and their implications on the specific didactical use of online and face-to-face peer-reviewing

A Heuristic Query Optimization Approach for Heterogeneous Environments

In a rapidly growing digital world the ability to discover, query and access data efficiently is one of the major challenges we are struggling today. Google has done a tremendous job by enabling casual users to easily and efficiently search for Web documents of interest. However, a comparable mechanism to query data stocks located in distributed databases is not available yet. Therefore our research focuses on the query optimization of distributed database queries, considering a huge variety on different infrastructures and algorithms. This paper introduces a novel heuristic query optimization approach based on a multi-layered blackboard mechanism. Moreover, a short evaluation scenario proofs our investigations that even small changes in the structure of a query execution tree (QET) can lead to significant performance improvements.

A Domain Specific Language and Workflow Execution Engine to Enable Dynamic Workflows

Workflow engines often being based on WS-BPEL, currently rely on a mix of recovery / modification strategies that are either part of the workflow description, part of the workflow engine, or realized as plugins to the workflow engine. To foster the development of distributed cloud-based workflow engines and novel repair algorithms, workflow engines have to be modularized in order to overcome the static and inflexible APIs provided by these workflow engines. Dynamic features gained by a modularization include the creation of external modules to monitor as well as modify a workflow to provide error handling in conjunction with Service Level Agreement (SLA) constraints. The aim of this paper is to present a flexible Workflow Execution Engine to facilitate the development of a new dynamic infrastructure to realize dynamic workflow engines with a focus on cloud-based environments.

Towards Dynamic Authentication in the Grid — Secure and Mobile Business Workflows Using GSet

Until now, the research community mainly focused on the technical aspects of Grid computing and neglected commercial issues. However, recently the community tends to accept that the success of the Grid is crucially based on commercial exploitation. In our vision Foster’s and Kesselman’s statement “The Grid is all about sharing.” has to be extended by “... and making money out of it!”. To allow for the realization of this vision the trust-worthyness of the underlying technology needs to be ensured. This can be achieved by the use of gSET (Gridified Secure Electronic Transaction) as a basic technology for trust management and secure accounting in the presented Grid based workflow. We present a framework, conceptually and technically, from the area of the Mobile-Grid, which justifies the Grid infrastructure as a viable platform to enable commercially successful business workflows.