An Optimization Method Of Product Oil Distribution Considering Drivers’ Workload Balance

As a country with large population and large automobile consumption,China is now facing the ever-growing demand and increasingly onerous distribution tasks of petrol oil.The conflict between the increasingly heavy distribution task and the scarcity of tanker drivers has increased the risk of overtime working and fatigue driving as well as the disparity between driver’s workload and salary,the rate of resignation,the drivers’ psychological imbalance and other issues.Drivers’ unhealthy physical and psychological condition will not only reduce the efficiency of distribution tasks,but also have direct threat to the public safety,and even cause the traffic accidents.Therefore,it is urgent to do some research of product oil distribution considering drivers’ workload balance.The problem of product oil distribution considering drivers’ workload balance can be modeled as a special variant of Vehicle Routing Problem(VRP).The Vehicle Routing Problem with Route Balancing(VRPRB)is worth mentioning because it is very similar to this problem.What’s more,this problem also has features of other two important variants named The Petrol Station Replenishment Problem(PSRP)and Multi-Trip Vehicle Routing Problem(MTVRP).This problem presents many new challenges remained to be tackled because it is a multi-trip,multi-compartment,multi-product and multi-objective VRP which has been proved to be NP-hard problem.In terms of this problem,the main work of this research is as follows:(1)Analysis of the product oil distribution problem considering drivers’ workload balance.Firstly,this paper describes the background of the problem.Then,we expound the characteristics and the complexity of this problem and other aspects.Finally,the solution of this problem is proposed.(2)A multi-objective optimization model of the product oil distribution problem considering drivers’ workload balance.This paper presents a model comparing drivers’ workload by means of Adams’ s equity theory,integrating it with the traditional model of product oil distribution,and a multi-objective optimization model of product oil distribution considering drivers’ workload balance is proposed with the objective of minimizing the total cost and the balance disparity.(3)A multi-objective heuristics algorithm for the product oil distribution problem.Considering the characteristics of this problem,this paper proposes a heuristic algorithm by introducing a two-stage Split_Assign procedure to generate and assign the routes.Two strategies are also embedded in the algorithm structure to improve the efficiency.(4)Numerical experiments and application research.This paper verifies the efficiency of the proposed model and algorithm by testing the numerical cases based on real-life investigation.The managerial implication is also presented.This study can support the decision-making of product oil distribution plans as well as other similar problems with the requirement of workload balance.What’s more,this study also enriches the optimization theories of VRP under multi-disciplines,and it may attach some enlightening significance to considering human behavior in the scheduling system.