OPEDo is a software tool for the optimization of discrete event systems according to performance or dependability measures. The tool can be seen as an add on to various tools for performance and dependability analysis. The goal of OPEDo is to provide a wide variety of optimization algorithms for complex black box functions as they are required for the model based optimization of discrete event systems using analytically tractable models or simulation models. The paper introduces the software architecture of the tool, gives a brief sketch of the integrated optimization algorithms and presents several examples.

In this paper we present a tool for the analysis of hierarchical service-oriented extended open fork/join queueing networks (EOFJQNs). The tool especially focusses on application areas that consider a service-oriented respectively processoriented view of systems. Such application areas are for example business process management, logistics, supply chain management, production planing and control, and computer and communication systems. Since parallel process execution is a typical property of corresponding models we consider extended queueing networks that incorporate complex fork/join structures. For the analysis of EOFJQNs we apply a frequently used decomposition approach and we additionally approximate inter-arrival times and service times with phase-type distributions. Then the analysis of the isolated nodes is based on their underlying quasi-birth-and-death process. In this context the main problem is the analysis of complex fork/join structures. Therefore, at first we briefly reflect an approach for the analysis of rather simple fork/join nodes and afterwards apply a new aggregation techniques that allows us to reduce complex fork/join structures to simple fork/join nodes. We apply our tool to the analysis of a parallel production line.

In this paper we present a new approach for the analysis of extended fork/join queueing networks. We consider networks of queues with phase-type distributed inter-arrival and service times whose dynamic behaviour can be mapped to Quasi-Birth-and-Death processes (QBD). We furthermore allow for the existence of fork/join nodes that synchronise several parallel subnets. The analysis of this type of queueing networks is based on the well-known decomposition approach by Kuhn/Whitt. To deal with fork/join subnets we apply a method of Balsamo et al. They consider the isolated analysis of a simple type of fork/join nodes that synchronise several single server queues with (heterogenous) phase-type distributed service times and a common phase-type distributed inter-arrival process. We extend this technique to the analysis of extended fork/join nodes that synchronise several parallel networks of queues instead of single server queues. Therefore, we apply a new aggregation technique that reduces the analysis of extended fork/join nodes to the analysis of simple fork/join nodes.