This study presents optimization models for large vehicle routing problems using a spreadsheet solver and Python programming language with extended graphic card boosting computing power. Near optimality is feasible and attainable with spreadsheet tools and models for solving real-life problems....

We present a novel relaxation for general nonconvex sparse MINLP problems, called overlapping convex hull relaxation (CHR). It is defined by replacing all nonlinear constraint sets by their convex hulls. If the convex hulls are disjunctive, e.g. if the MINLP is block-separable, the CHR is...