Stefan Appel

I was a PhD student in the area of event-driven computing from 2009 to 2014. I have worked on the integration of event-based systems (EBSs) with business processes. Currently, I am working at Siemens AG in the areas of Cloud Computing and Big Data.

Research Statement

Business process modeling and execution is widely adopted in enterprises. Processes are modeled by business experts and executed inside a Service-oriented Architecture (SOA). Since services follow the request/reply paradigm, they are not the natural fit to integrate real-world information with business processes in a reactive way. Information reflecting the status of the real world is rather available in form of continuous streams of events.

My research focuses on concepts and technologies to allow the seamless integration of these event streams with business process modeling and execution. I work on methods that integrate event streams with the Business Process Modeling Notation (BPMN) as well as on a service-like component model for the integration of event streams at the IT infrastructure layer.

I'm also working on performance evaluation of message-oriented middleware (MOM). Message-oriented middleware, in particular publish/subscribe-based communication, is the backbone for event-based interactions. Therefore, a reliable and scalable event dissemination infrastructure is crucial in event-based systems.

Research Projects and Cooperations

Software Campus Integration of Event Streams with Business Processes
Software Campus Project
Industrial Partner: Software AG
Software-Cluster Software Innovation for the Digital Enterprise
Software-Cluster
ADiWa Alliance Digital Productflow Secure PubSub Privacy-preserving Publish/Subscribe
Collaboration with Purdue University (USA)
ActiveMQ Performance Evaluation with SPECjms2007
Evaluation of Apache ActiveMQ
Evaluation of JBoss HornetQ
Dagstuhl Dagstuhl Seminar
Event Processing

Functions & Memberships

2nd International Workshop on Event Modeling and Processing in Business Process Management - EMoV 2015
Co-Chair
Standard Performance Evaluation Corporation
Primary Representative TU Darmstadt (2010-2014)
TU Darmstadt
Mitglied der Universitätsversammlung (2011-2013)
Mitglied des Haushaltsausschusses (2010-2013)
Mitglied des Senats (2012-2013)
Software Campus Software Campus
Member
Industrial Partner: Software AG
Gesellschaft für Informatik e.V.
Member

Teaching

Summer 2013 Event Processing Lab
Winter 2012/13 Middleware
Winter 2011/12 Middleware
Summer 2011 Distributed Reactive Software Systems

Publications

Google Scholar Citations, DBLP

I have an Erdős Number of 3 (via Elisa Bertino).

2014
Integration of Event Processing with Service-oriented Architectures and Business Processes (PhD Thesis)
Stefan Appel
Technische Universität Darmstadt, Darmstadt, Germany, tuprints, May 2014
[PDF] [BibTeX]
 
Modeling and Execution of Event Stream Processing in Business Processes
Stefan Appel, Pascal Kleber, Sebastian Frischbier, Tobias Freudenreich, Alejandro Buchmann
Information Systems, ISSN 0306-4379, Elsevier, 2014
The final publication is available at http://dx.doi.org/10.1016/j.is.2014.04.002
[Journal] [PDF] [BibTeX]
 
2013
Implementing Federated Object Systems
Tobias Freudenreich, Patrick Eugster, Sebastian Frischbier, Stefan Appel, Alejandro Buchmann
In Giuseppe Castagna: ECOOP 2013 – Object-Oriented Programming, Lecture Notes in Computer Science 7920, ISBN 978-3-642-39037-1, Springer Berlin Heidelberg, July 2013
[PDF] [BibTeX]
 
Privacy Preserving Context Aware Publish Subscribe Systems
Mohamed Nabeel, Stefan Appel, Elisa Bertino, Alejandro Buchmann
7th International Conference on Network and System Security (NSS), Madrid, Spain, June 2013
Best Paper Award
[Conference] [PDF] [BibTeX]
 
Event Stream Processing Units in Business Processes
Stefan Appel, Sebastian Frischbier, Tobias Freudenreich, Alejandro Buchmann
11th International Conference on Business Process Management (BPM), Beijing, China, 2013
[PDF] [BibTeX]
 
Privacy Preserving Context Aware Publish Subscribe Systems
Mohamed Nabeel, Stefan Appel, Elisa Bertino, Alejandro Buchmann
Technical Report, No. CERIAS TR 2013-01, Center for Education and Research in Information Assurance and Security (CERIAS), Purdue University, 2013
[PDF] [BibTeX]
 
2012
Eventlets: Components for the Integration of Event Streams with SOA
Stefan Appel, Sebastian Frischbier, Tobias Freudenreich, Alejandro Buchmann
5th IEEE International Conference on Service-Oriented Computing and Applications (SOCA), Taipei, Taiwan, December 2012
Best Paper Award
[Conference] [PDF] [BibTeX]
 
From Calls to Events: Architecting Future BPM Systems
Alejandro Buchmann, Stefan Appel, Tobias Freudenreich, Sebastian Frischbier, Pablo E. Guerrero
10th International Conference on Business Process Management, BPM '12, Tallinn, Estonia, Springer, September 2012
[PDF] [BibTeX]
 
ACTrESS - Automatic Context Transformation in Event-based Software Systems
Tobias Freudenreich, Stefan Appel, Sebastian Frischbier, Alejandro Buchmann
Proceedings of the 6th ACM International Conference on Distributed Event-Based Systems, DEBS '12, Berlin, Germany, ISBN 978-1-4503-1315-5, ACM, New York, NY, USA, July 2012
[PDF] [BibTeX]
 
Sound Transformations for Message Passing Systems
Patrick Eugster, Tobias Freudenreich, Sebastian Frischbier, Stefan Appel, Alejandro Buchmann
Technical Report, TU Darmstadt, 2012
[PDF] [BibTeX]
 
2010
Event-Driven Services: Integrating Production, Logistics and Transportation
Alejandro Buchmann, Hans-Christian Pfohl, Stefan Appel, Tobias Freudenreich, Sebastian Frischbier, Ilia Petrov, Christian Zuber
2nd International Workshop on Service Oriented Computing in Logistics (SOC-LOG), San Francisco, USA, December 2010
[PDF] [BibTeX]
 
A Logistics Workload for Event Notification Middleware
Stefan Appel, Kai Sachs
In Kai Sachs, Ilia Petrov, Pablo Guerrero: From Active Data Management to Event-Based Systems and More, Lecture Notes in Computer Science 6462, ISBN 978-3-642-17225-0, Springer, November 2010
[PDF] [BibTeX]
 
Towards Benchmarking of AMQP
Stefan Appel, Kai Sachs, Alejandro Buchmann
4th ACM International Conference on Distributed Event-Based Systems (DEBS), July 2010
[PDF] [BibTeX]
 
Quality of Service in Event-based Systems
Stefan Appel, Kai Sachs, Alejandro Buchmann
22nd GI-Workshop on Foundations of Databases (GvD), Bad Helmstedt, Germany, May 2010
[PDF] [BibTeX]
 
Benchmarking Publish/Subscribe-based Messaging Systems
Kai Sachs, Stefan Appel, Samuel Kounev, Alejandro Buchmann
Database Systems for Advanced Applications: DASFAA 2010 International Workshops: BenchmarX'10, LNCS, Berlin, Heidelberg, Springer-Verlag, 2010
[PDF] [BibTeX]
 
Performance Evaluation of Multi Machine Virtual Environments
Stefan Appel, Ilia Petrov, Alejandro Buchmann
Proceedings of the 2010 SPEC Benchmark Workshop, Paderborn, Germany, 2010
[PDF] [BibTeX]
 
2009
Benchmarking of Message-Oriented Middleware
Kai Sachs, Samuel Kounev, Stefan Appel, Alejandro Buchmann
Proceedings of the International Conference on Distributed Event-Based Systems (DEBS 2009), Nashville, TN, USA, July 2009
[Conference] [PDF] [BibTeX]
 
A Performance Test Harness For Publish/Subscribe Middleware
Kai Sachs, Samuel Kounev, Stefan Appel, Alejandro Buchmann
SIGMETRICS/Performance 2009 Demo Competition, June 2009
[Conference] [PDF] [BibTeX]
 
2008
Lokalisierung in mobilen Ad-hoc-Netzen ohne zusätzliche Infrastruktur
Stefan Appel, Peter Ebinger
ISBN 978-3639064933, VDM Verlag Dr. Müller, August 2008
[BibTeX]
 
Angriffserkennung in MANETs basierend auf Entfernungsschätzungen
Stefan Appel, Peter Ebinger
D-A-CH Security, Berlin, Germany, 2008
[Conference] [BibTeX]
 

Supervised Theses

Integration of Event Streams into EPCs and Software AG's Model-to-Execute Process (BSc. Thesis)
Pascal Kleber. Technische Universität Darmstadt, October 2013
[BibTeX]
 
Continuous Auditing im Prüfungswesen (Master's Thesis)
Emal Rahman. TU Darmstadt, 2013
[BibTeX]
 
Evaluating Intelligent Routing Mechanisms in Distributed Message-oriented Middleware (Master's Thesis)
Jan Matuschek. Technische Universität Darmstadt, March 2012
[BibTeX]
 
XML Integration into an SQL-based CEP Engine (Master's Thesis)
Martin Prodanov. TU Darmstadt, 2012
[BibTeX]
 
Automatic Context Transformation in Complex Event Processing Systems (Msc. Thesis)
Tobias Freudenreich. Technische Universität Darmstadt, February 2011
[BibTeX]
 

Background and Degrees

Stefan Appel

Contact

Stefan Appel

A A A | Print | Contact | Legal note | Search