Abstract
This paper presents a multi-channelled supply chain network equilibrium (SCNE) model with the behaviour of freight carriers, which is developed to represent the trading chain of cocoa in Sulawesi, Indonesia. The model takes into account the behaviour of local collectors, local traders, exporters, and freight carriers. Utilising this SCNE in the lower level, a combinatorial optimisation is undertaken in the upper level within the framework of mathematical programmes with equilibrium constraints, where a suitable set of transport network improvement actions is selected from a number of possible actions for improving the efficiency of cocoa supply chain network (SCN). The upper level is solved with a modified probability- based discrete binary particle swarm optimisation. Finally, the model is applied to an actual cocoa SCN in Sulawesi for investigating the impact of transport measures to the international trading of cocoa.
