(Stochastic) Petri Nets

Petri nets, introduced by Carl Adam Petri more than fifty years a ago, is a graphical mathematical modeling framework that comes in many flavors. Despite considerable efforts for standardization of Petri nets, there is still an often confusing abundance of different versions; to this end, an Italian proverb Ogni sacarrafone è bello a mamma sua ("Every cockroach is beautiful to his mother") used by M. A. Marsan back in 1990 (M. A. Marsan Stochastic Petri Nets: an Elementary Introduction," Volume 424 of Lecture Notes in Computer Science, 1–29. Springer) remains quite relevant.