The use of Coxian distribution in closed-form treatment of stochastic Petri nets

In this paper we propose a method for delay approximation in stochastic Petri nets. The method is based on utilization of Coxian distribution and least square fitting criteria. The problem is reduced to a direct parameters identification. Two examples illustrate the method application. The first one demonstrates approximation of power outage duration at a 200 MW power plant unit. Degree of a phase-type distribution resulting from a fork-join structure is reduced in the second example.