Multi-stage Cold Chain Scheduling For Perishable Products

With the development of social economy, people’s life quality keep increasing, and correspondently, the demand for cold chain products increases. As cold chain products are perishable, more coordination is needed in the production and distribution of such products, and thus, multi-stage joint optimization is needed for the corresponding scheduling problems in cold chain enterprises.This dissertation considers the multi-stage cold chain scheduling problem with perishable products. This dissertation introduces the background, importance, content and method firstly, then reviews literature in this field. In addition, this dissertation studies two branches issues in cold chain environment, which are 1) the integrated problem of production and 2) batch delivery and the integrated problem of production and distribution.Firstly, this dissertation considers the integrated problem of production and batch delivery in cold chain environment. Manufacturers produce products of multiple orders on a single machine, then deliveries them to customers by several identical vehicles. Extra deteriorating cost is incurred as the products will deteriorate with time passed by, meanwhile, vehicle cost is incurred from the delivery. So it is necessary to arrange production and delivery batches reasonably to minimize the total cost including vehicles cost and deteriorating cost. Problem analysis is done firstly to present several properties of optimal solutions, based on which two algorithms are proposed:priority of vehicle with minimum residual volume algorithm and priority of vehicle with minimum total order processing time. Then a lower bound is proved. Finally the validity and efficiency of those two algorithm are shown by large-scale experiments of random data.Subsequently, this dissertation considers the integrated problem of production and distribution in cold chain environment. Manufacturer produces products of multiple orders from different customers on a single machine, then deliveries them to customers by several identical vehicles. In order to minimize the total cost including deteriorating cost, vehicles cost and customers waiting cost, manufacturers need to arrange the sequences of production and distribution. Problem analysis is done firstly to present several properties of optimal solutions, based on which simulated annealing algorithm is proposed. Finally, large-scale experiments of random data shows that the simulated annealing algorithm is better than two-stage algorithm.