  Green supply chain is an emerging approach in supply chain management to
reduce environmental impact of the process concerning the flow of goods and
materials. As a discrete-event system, supply chain can be modeled using Petri
Nets. Colored Petri Nets (CPNs) extend the classical Petri net formalism with
data, time and hierarchy. These extensions makes it possible to deal with the
green aspects of the supply chain.This paper deals with the Colored Petri Net
approach to model and simulate a green supply chain system. The forward supply
chain network starts from the raw material suppliers, to the manufacturers,
wholesalers, retailers and to the final customers. The reverse supply chain
network is made of collecting points, recycling plants, disassembly plants,and
secondary material market. A government environment agency plays the role of
regulation of the recycling process. A colored Petri net model of the green
supply chain is developed and simulated with CPN Tools, a dedicated software
for CPN models. The simulation results as well as the state-space analysis
results validate the correctness of the model.
