Uncertain Cross Docking Scheduling: Modles And Algorithms

This paper studies car factory inbound uncertain cross docking scheduling problem. Inbound logistics is an important component of the lean production system. It is also known to be the most complex logistics service that needs advanced technology. In cross docking, distribution center only receive and send materials, with few materials in store. Cross docking can reduce or eliminate inventory and therefore space requirements, cut moving cost inside cross docking center and transportation cost. Uncertainties are main factors that lead to inefficiency of logistics, and among transportation uncertainty is important for auto inbound logistics. This paper focus on the transportation uncertainty of auto inbounds logistics.The transportation mode of inbound logistics mainly consisted of direct delivery and milk run. Milk run is appropriate for transportation of high frequency and small lot, while direct delivery is suitable for transportation of large quantity and full truck load. This paper investigates both of them. According to the number of the inbound and outbound cars, cross docking scheduling modes can be classified by basic cross docking scheduling mode and flexible cross docking scheduling mode. Three problems are studied as follows.1) Uncertain basic cross docking scheduling problem. We first study the most basic and the simpliest model of the problem hoping that will give me more principles and ways to study more complex problems. This paper builds mix integral models under certain and uncertain environment firstly and then solves them using ILOG CPLEX for small scale instances. Then we present four heuristics and designs numerical experiment to check their performances. We further present a method to revise expectation of the transportation time according to real data getting from logistics company. Numerical experiment is finally given to check out the different performances before and after revised.2) Uncertain flexible cross docking scheduling problem. Flexible cross docking scheduling refers to more than one inbound or outbound trucks. Besides the same methods used for basic problem, random scheduling algorithm is constructed to evaluate performance of heuristics. The worst performance ratio of heuristics are also analyzed.3) Uncertain milk run cross docking scheduling problem. This part assumes one truck in inbound and outbound stage respectively, milk run in inbound, and direct delivery in outbound procedure. Similarly, certain and uncertain mixed integral models are established and a heuristic and taboo search are proposed. Computational experiments show the efficiency of heuristic as well as tabu search.This paper studies models and algorithms for some issual problems occurring in auto inbound logistics. These results are helpful for logistics managers to make better decision in practice.