MOE-DGSCND: Multi-Objective Enterprise Green Supply Chain Network Design

This paper introduces and studies the Multi-Objective Enterprise Doubly-Green Supply Chain Network Design (MOE-DGSCND) problem, an extension of Multi-Objective Supply Chain Network Design. The problem studied here is a three-objective combinatorial optimization problem that simultaneously minimizes total cost f1, carbon dioxide emissions f2 and customer dissatisfaction f3 over binary decisions regarding which distribution centers to open and how to assign customer zones to open facilities. The problem generalizes the capacitated facility location problem (CFLP) and is known to be NP-hard (Garey and Johnson, 1979). This paper formally specifies the decision variables, objective functions and constraints and investigates three solution approaches using a single numerical instance: (A) an exact weighted-sum integer linear programming (ILP) formulation solved with Python combinatorially and via PuLP, (B) three Fully Polynomial-Time Approximation Schemes (FPTAS) providing (1 + $\epsilon$)-approximate solutions for $\epsilon$ := 0.15 and (C) two baseline heuristics for comparison. On an instance with eight customers and five candidate distribution centers, the exact solver certifies the optimal (sampled) supported solutions across eight weight combinations, while the FPTAS-based approaches complete within milliseconds, compared to centiseconds for the exact ILP on this tiny non-stochastic instance.