Petri net

[′pē·trē ‚net] (communications) An abstract, formal model of information flow, which is used as a graphical language for modeling systems with interacting concurrent components; in mathematical terms, a structure with four parts or components: a finite set of places, a finite set of transitions, an input function, and an output function.

Petri net

(parallel, simulation)A directed, bipartite graph inwhich nodes are either "places" (represented by circles) or"transitions" (represented by rectangles), invented by CarlAdam Petri. A Petri net is marked by placing "tokens" onplaces. When all the places with arcs to a transition (itsinput places) have a token, the transition "fires", removing atoken from each input place and adding a token to each placepointed to by the transition (its output places).

Petri nets are used to model concurrent systems,particularly network protocols.

Variants on the basic idea include the coloured Petri Net,Time Petri Net, Timed Petri Net, Stochastic Petri Net,and Predicate Transition Net.

FAQ.

Petri Net

A diagram that models the behavior of a system. Developed by Carl Adam Petri in the early 1960s, the Petri Net symbols are "places" (circles) that represent system states and "transitions" (rectangles) that show actions, both connected by arrows known as "arcs."

Petri Net Symbols

Petri Nets are often used to show concurrency as in example #2.