A hybrid framework for the modelling and optimisation of decision problems in sustainable supply chain management

Abstract

This paper describes the hybrid framework for the modelling and optimisation of decision problems in sustainable supply chain management. The constraint-based environments used so far to model and solve the decision-making problems have turned out to be ineffective in cases where a number of interbound variables are added up in multiple constraints. The hybrid approach proposed here combines the strengths of mathematical programming and constraint programming. This approach allows a significant reduction in the search time necessary to find the optimal solution, and facilitates solving larger problems. Two software packages, LINGO and ECLiPSe, were employed to solve optimisation problems. The hybrid method appears to be not only as good as either of its components used independently, but in most cases it is much more effective. Its advantages are illustrated with simplified models of cost optimisation, for which optimal solutions are found ten times faster. The application of the proposed framework has contributed to more than 20 fivefold reduction in the size of the combinatorial problem.