Determination of delay times in failure afflicted networked automation systems using probabilistic model checking

The determination of delay times in failure afflicted Networked Automation Systems (NAS) is a new challenge for automation engineers. In addition to the new system structures of NAS which share one or more common devices delays resulting from internal network processes have to be taken into account. Furthermore, the considerable influence of data transmission between several asynchronously executed cyclic processes on system performance should not be neglected in a work on delay times. This paper introduces a modular modeling approach for NAS based on probabilistic timed automata. The generated models allow the determination of delay times by the use of probabilistic model checking (PMC). To illustrate the concept it is applied to a case study determining reliability properties of a NAS.