An effective heuristic for solving a combined cargo and inventory routing problem in tramp shipping

Abstract

In this paper a vendor managed inventory (VMI) service in tramp shipping is considered. VMI takes advantage of introducing flexibility in delivery time and cargo quantities by transferring inventory management and ordering responsibilities to the vendor which in this case is a shipping company. A two-phase heuristic is proposed to determine routes and schedules for the shipping company. The heuristic first converts inventories into cargoes, thus turning the problem into a classic ship routing and scheduling problem. It then uses adaptive large neighborhood search to solve the resulting cargo routing and scheduling problem. The heuristic iteratively changes the cargoes generated to handle the customer's inventories, based on the information obtained from an initial solution. Computational results are presented, discussed and compared with exact solutions on large realistic instances. The results reveal the potential savings from converting traditional contracts of affreightment to an integrated VMI service. The factors that influence the benefits obtainable through VMI are also analyzed.

Optimization on the Multi-period Empty Container Repositioning Problem in Regional Port Cluster Based upon Inventory Control Strategies

“…at period T , and the probability of the state ST 2 T i for the p T −1 (a T −1 ), the total cost at this time is showed in formula (25). Thus, in the T − 2 stage, the total cost is showed by formula (26). In the t stage, the total cost for the period t − T is showed in formula (27).…”

“…Jiang and Grossmann [25] proposed two mixed integer linear programming models, continuous and discrete, to optimize the inventory and repositioning volume. Hemmati et al [26] designed a heuristic algorithm for the inventory and route selection of tramp ships, and optimized the inventory and transport route selection. De et al [27] studied the inventory route problem by taking container ships with time window constraints as the research object.…”

Tramp ship routing and scheduling with voyage separation requirements

“…However, even with the heuristic approach they are only able to solve small sized instances where only few VMI services are introduced, and running times increase drastically from seconds to days with increases in problem size or in the number of VMIs. Hemmati et al (2015) continue the work from Stålhane et al (2014) in order to develop a more efficient method for the same problem, i.e. for a tramp ship routing and scheduling problem with inventory constraints.…”

Solving multi-product inventory ship routing with a heterogeneous fleet model using a hybrid cross entropy-genetic algorithm: a case study in Indonesia

“…A mixed integer programming model and an adaptive large neighborhood search-based heuristic were proposed to solve the problem. Hemmati, Stålhane, Hvattum, and Andersson (2015) discussed a VMI service application in tramp shipping. A two-phase heuristics was proposed to determine routes and schedules for a shipping company.…”