Performability: Reliability and Performance Analysis of Stochastic Networks

This is a joint project with Cornelia Sauer.
We consider stochastic networks (networks of queues) where nodes or the servers at the nodes are degradable, i.e., the nodes may be subject to breakdown or perturbations, which decrease their capacity. Following this, repair mechanisms and repair strategies are introduced. Our aim is to find network models where the performance behaviour of the network and the breakdown and repair mechanism are incorporated into a unified Markovian system description, which nevertheless admits an explicit steady state.
Collaboration with Jennifer Mylosz (University of Hamburg).

Some recent articles concerning Performability: Reliability and Performance Analysis of Stochastic Networks :

1. Modeling networks with unreliable servers (with Cornelia Sauer)
   Proceedings of the 2. MMB–Arbeitsgespräch Leistungs-, Zuverlässigkeits und Verlässlichkeitsbewertung von Kommunikationsnetzen und verteilten Systemen, Berichte des Fachbereichs Informatik der Universität Hamburg No. 242, 83 – 90, Hamburg 2002.
2. Separable networks with unreliable servers (with Cornelia Sauer)
   in Charzinski, J; Lehnert, R.; Tran–Gia, P. (eds.): Providing Quality of Service in Heterogeneous Environments (Proceedings of the 18 ITC, Berlin), Teletraffic Science and Engineering Vol 5b, 821 – 830, Elsevier 2003.
   Extended version: BCMP networks with unreliable servers (with Cornelia Sauer)
   Preprint No.2003–01, Schwerpunkt Mathematische Statistik und Stochastische Prozesse, University of Hamburg 2003.
3. Availability formulas and performance measures for separable degradable networks (with C. Sauer)
   Economic Quality Control, 18, 165 – 194, 2003
4. Degradable networks with general up and down time distributions. (with C. Sauer)
   in: Buchholz, P.; Lehnert, R.; Pioro, M. (eds.): MMB & PGTS 2004,
   Proceedings of the 12th GI/ITG Conference on Measuring, Modelling and Evaluation of Computer and Communications Systems and 3rd Polish–German Teletraffic Symposium, 185 – 194, 2004
   Extended Version: Preprint No.2004–04, Schwerpunkt Mathematische Statistik und Stochastische Prozesse, University of Hamburg 2004.
5. Dependence ordering for queueing networks with breakdown and repair (with Cornelia Sauer, Rafal Kulik, Ryszard Szekli)
   Probability in the Engineering and Informational Sciences 20, 575–594, 2006
   also available as: Isotone differences ordering for unreliable Markovian queueing networks, Preprint No.2005–04, Schwerpunkt Mathematische Statistik und Stochastische Prozesse, University of Hamburg 2005, submitted.
6. Discrete time queueing networks with product form steady state: Availability and performance analysis in an integrated model (with Christian Malchin)
   Preprint No.2006–02, Schwerpunkt Mathematische Statistik und Stochastische Prozesse, University of Hamburg 2006, submitted.
7. On the behavior of stable subnetworks in non-ergodic networks with unreliable nodes (with Jennifer Mylosz)
   Computer Networks 53 (8), 1249–1263, 2009