Distributed Computing
ETH Zurich

Discrete Event Systems (HS 2007)

Over the past few decades the rapid evolution of computing, communication, and information technologies has brought about the proliferation of new dynamic systems. A significant part of activity in these systems is governed by operational rules designed by humans. The dynamics of these systems are characterized by asynchronous occurrences of discrete events, some controlled (e.g. hitting a keyboard key, sending a message), some not (e.g. spontaneous failure, packet loss).

The mathematical arsenal centered around differential equations that has been employed in systems engineering to model and study processes governed by the laws of nature is often inadequate or inappropriate for discrete event systems. The challenge is to develop new modeling frameworks, analysis techniques, design tools, testing methods, and optimization processes for this new generation of systems.

In this lecture we give an introduction to discrete event systems. We start out the course by studying popular models of discrete event systems, such as automata and Petri nets. In the second part of the course we analyze discrete event systems. We first examine discrete event systems from an average-case perspective: we model discrete events as stochastic processes, and then apply Markov chains and queuing theory for an understanding of the typical behavior of a system. In the last part of the course we analyze discrete event systems from a worst-case perspective using the theory of online algorithms and adversarial queuing.

Course language: German

Lecture by Prof. Roger Wattenhofer Thursday 13.15-15.00 @ ETF E1.

Exercises by Stefan Schmid and Roland Flury, Thursday 15.15-17.00 @ ETF E1.

Final Exam

The final exam is scheduled for 23. January 2008, 9:00-12:00 @ ETF E1. The duration of the exam is 3 hours.

To get a feeling of our examination style, you may look at our sample exam.

Note that the sample solutions to exercises of previous years are now again available for download.

NEW: Question Wiki

We provide a simple DES Question Wiki where we try to answer your questions such that we don't have to type the same answers several times. Questions requiring longer answers will be postponed to the question session.

Question Session

We held a question session in which we (try to) answer your questions about this lecture. The session is scheduled for Wednesday, 16. January 2008, 14:00 - 15:00, room ETF E1.

Please send us your questions ahead of time, at the latest until Tuesday, 15. January 2008 at 14:00 by email.

Related Semester / Master Thesis

During the exercise lecture of 6.12.07, Kai Lampka has presented several open semester and master thesis in the field of Petri nets / Markov chain modelling [slides]. If interested, please feel free to contact him directly.

Lecture material

Title Slides Additional Material References

Chapter 0
PDF 1:1
PDF 4:1

Chapter 1
Automata and Languages
PDF 1:1
PDF 4:1

Chapter 2
Smarter Automata
PDF 1:1
PDF 4:1

Chapter 3
Specification Models
PDF 1:1
PDF 4:1

Chapter 4
Stochastic Discrete Event Systems
PDF 1:1
PDF 4:1

Chapter 5
Worst Case Event Systems
PDF 1:1
PDF 4:1
Mario und Luigi

Chapter 6
Network Calculus
PDF 1:1
PDF 4:1

Exercise material

Title Exercise Sample Solution

Exercise 1
Assigned: 27/09/2007
Due: 11/10/2007

Exercise 2
Assigned: 11/10/2007
Due: 18/10/2007

Exercise 3
Assigned: 18/10/2007
Due: 25/10/2007

Exercise 4
Assigned: 25/10/2007
Due: 1/11/2007

Exercise 5
Assigned: 1/11/2007
Due: 8/11/2007

Exercise 6
Assigned: 8/11/2007
Due: 15/11/2007

Exercise 7
Assigned: 15/11/2007
Due: 22/11/2007

Exercise 8
Assigned: 22/11/2007
Due: 29/11/2007

Exercise 9
Assigned: 29/11/2007
Due: 6/12/2007

Exercise 10
Assigned: 6/12/2007
Due: 13/12/2007
Download , Notes

Exercise 11
Assigned: 13/12/2007
Due: 21/12/2007


You do not need a Testat to attend the final exam. However, if you need a Testat, e.g. because you don't intend to take the final exam, but need an attestation that you attended the class, you need to hand in at least 80% of the exercises.


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Dimitri Bersekas, Robert Gallager
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[borodin] Online Computation and Competitive Analysis
Allan Borodin, Ran El-Yaniv.
Cambridge University Press, 1998
[boudec] Network Calculus
J.-Y. Le Boudec, P. Thiran
Springer, 2001
[cassandras] Introduction to Discrete Event Systems
Christos Cassandras,Stéphane Lafortune.
Kluwer Academic Publishers, 1999, ISBN 0-7923-8609-4
[fiat] Online Algorithms: The State of the Art
A. Fiat and G. Woeginger
[hochbaum] Approximation Algorithms for NP-hard Problems (Chapter 13 by S. Irani, A. Karlin)
D. Hochbaum
[murata] Petri Nets: Properties, Analysis and Applications
Tadao Murata
Proceedings of the IEEE, vol. 99, issue 4, April 1989. pp. 541--580
[schickinger] Diskrete Strukturen (Band 2: Wahrscheinlichkeitstheorie und Statistik)
T. Schickinger, A. Steger
Springer, Berlin, 2001
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Michael Sipser.
PWS Publishing Company, 1996, ISBN 053494728X