Reseach On The Two-Stage Cross Docking Scheduling Problem And Its Algorithms

This paper studies the so called two-stage cross docking logistics scheduling problem and its algorithms. Cross docking, as a relative new distribution method, is to move goods directly from receiving to shipping with the objective to eliminate the inventory-holding and order picking functions of warehouse while keeping the receiving and shipping functions. The advantage of cross docking is to implement the scale economy of transportation without increasing the storage in distribution center, and hence reduce logistics costs and production leadtimes.By analyzing the operational flows, cross docking types and its implementary conditions, a two-stage cross docking scheduling model for the problem has been built, in which the receiving and shipping stages are considered as two machines respectively, and the receiving and shipping goods as the jobs to process on these two machines. To describe the consolidation function of cross docking, one job on the second machine can not be processed unless its corresponding jobs have finished their processing on the first machine, with these imposed constraints, the following model is built: Given two sets of jobs, J1 and J2, two machines, M1 and M2, and a set of subsets of J1, each subset corresponding to a job in J2. Jobs in J1 are processed on machine M1 and jobs in J2 are processed on machine M2. Each job in J2 can be processed on M2 only after all jobs in the corresponding subset of J1 have been processed on M1. The objective is to minimize the total weighted completion time. Following the known standard classification scheme, our problem is denoted as F2︱CD︱∑ωjCj. whereωj is the weight of job J2j, and...