Hierarchical Structure of a Green Supply Chain

Abstract Since the past decades, environmental challenges have been increasing due to pollution and production costs. For sustainable development, a green supply chain integrates the sustainable environmental process into the traditional supply chain, reducing the cost of production, spur economic growth, and solving ecological issues. Thus, exploring the feasible design of green supply chain systems becomes an essential requirement for industry and commercial organisations. However, the green supply chain system usually integrates various systems currently used by the participants of supply chains. The design of such a large-scale system is quite costly through the conventional discrete event simulation-based approaches. Moreover, formal modelling method (e.g. Petri nets), as an alternative approach, provides formal and efficient support to model creation and analysis. However, the Petri nets cannot achieve compositional modelling, particularly for large-scale and complex systems, e.g., the green supply chain system. For improved compositionality, this paper proposes a hybrid modelling technique to integrate the compositional feature into Petri nets by combining with process algebra due to its superior capability in compositional modelling. The hybrid technique supports the modelling with Petri nets at first. It sorts the incidence matrix of Petri nets’ models to retrieves the mapping relation between Petri nets and performance evaluation process algebra (i.e. PEPA, a formal modelling method based on process algebra), which represents the compositional structure of Petri-net models. Hence, a compositional-structure constructing algorithm is designed to obtain all qualified PEPA hierarchical sub-models based on Petri net models, which combines Petri nets’ usability and the compositionality of PEPA for creating a novel and enhanced formal modelling technique that is particularly suitable for systems such as green supply chain systems.