A Diploid Evolutionary Algorithm for Sustainable Truck Scheduling at a Cross-Docking Facility

Maxim Dulebenets

doi:10.3390/su10051333

Maxim Dulebenets

Open Access

https://doi.org/10.3390/su10051333

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Abstract

Supply chains have become more time-sensitive in recent years. Delays in supply chain operations may cause significant negative externalities, including lost sales and customers. In order to facilitate the product distribution process within supply chains, reduce the associated delays, and improve sustainability of the supply chain operations, many distribution companies started implementing the cross-docking technique. One of the challenging problems in management of the cross-docking facilities is efficient scheduling of the arriving trucks. This study proposes a novel Diploid Evolutionary Algorithm for the truck scheduling problem at a cross-docking facility, which—unlike the Evolutionary Algorithms presented in the cross-docking literature to date—stores the genetic information from the parent chromosomes after performing a crossover operation. The objective of the formulated mathematical model is to minimize the total truck service cost. The conducted numerical experiments demonstrate that the optimality gap of the developed algorithm does not exceed 0.18% over the considered small size problem instances. The analysis of the realistic size problem instances indicates that deployment of the developed solution algorithm reduces the total truck handling time, the total truck waiting time, and the total truck delayed departure time on average by 6.14%, 32.61%, and 34.01%, respectively, as compared to a typical Evolutionary Algorithm. Furthermore, application of the diploidy concept decreases the total truck service cost by 18.17%.

Highlights

Nowadays the “just-in-time” concept plays a critical role in supply chains [1,2,3,4,5,6,7,8,9]
Since the cross-docking facility (CDF) truck scheduling problem is of a high complexity, a large number of various heuristic and metaheuristic algorithms were proposed in the cross-docking literature to obtain truck schedules of a good quality within an acceptable computational time
The cross-docking facilities provide the fast flow of products from the inbound trucks to the assigned outbound trucks, which further deliver the products to the final customers

Summary

Introduction

Nowadays the “just-in-time” concept plays a critical role in supply chains [1,2,3,4,5,6,7,8,9]. The key supply chain players, including manufacturers, logistics companies, distribution facility operators, and retailers, aim to minimize delays in their operations, as those delays may negatively affect the whole supply chain and may even result in lost sales and customers. The cross-docking technique has been heavily used in industry to facilitate the flow of different products within distribution facilities, support “just-in-time” deliveries within supply chains, and improve sustainability of the supply chain operations [1]. The inbound trucks, delivering various products from different manufactures, are assigned to the inbound doors of a cross-docking facility (CDF), where the products are unloaded from the inbound trucks (typically by forklift operators) and moved to the dedicated storage areas. The outbound trucks further deliver the products to the end customers. The cross-docking technique has been adopted by the largest retailers (e.g., Walmart, Target, COSTCO, Auchan), shipping companies (e.g., FedEx, UPS, USPS, DHL), and other private and public distribution companies across the world

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