Study On The Pickup Vehicle Routing Problem Based On JIT Supply

With the technique development of produce and logistics, the theory of Just In Time(JIT) has applied universally. The implementation of JIT management modern can reduce inventory level and cost furthest. Because the relationship of inventory cost and transport cost are antinomy, it will result in more transport cost while reduce inventory amount. So, the transportation of great efficiency and low cost are the ensurences to implement JIT supply successfully. The vehicle routing problem(VRP) which based on JIT supply, increase the restraint of inventroy at manufacturer, and present a more strict requirement of time windows. Besides the transport cost, the optimum object also includes the inventory cost. It exerts an important significance on the rationalization of vehicle route, ensuring the quality of transport service of JIT supply, and reducing the logistics cost.This paper studied the the pickup vehicle routing problem(VRP) which based on JIT supply. Considered the restraint of lower inventory at manufacturer, this paper designed the plan that each part source was being served by a single route run at a fixed frequency, but such routes had an optimized pickup frequency that performs multiple pickups. This paper mainly studied the optimization of vehicle routes under this situation,viz. milk run(MR) problem. After that, this paper set up the mathematical formulation of MR, designed Tabu Search algorithm to solve this formulation. Having adoption Savings Heuristics approach to generate the initial solution for the tabu search, using or-opt andλ-interchange to reach neighbourhood operation, in order to improve the routes.The tabu search algorithm was implentmented with C Compiler on computer, and applied the techniques to a real problem, proved the feasibility and validity of this algorithm; And else, this paper used a different plan from MR to solve the problem of VRP which based on JIT supply. The main concept of this plan was that permit multiple routes visit several nodes, and those routes may crisscross in time window of a same supplier. In this plan, each node had its own frequency, viz.General Frequency Routing(GFR). And compared the two plans, summed up each characteristics, provided reference for lucubrating on VRP based on JIT supply in the future.