Abstrakt
The Norwegian company EWOS AS produces fish feed for the salmon farming industry. It supplies approximately 300 customers spread along the coast of Norway.
The feed is produced at three factory locations and distributed by a fleet of dedicated vessels. The high seasonality of the demand and the large number of customers make the distribution planning a substantial challenge.
EWOS handles this challenge by operating a system of mostly fixed routes with decentralized planning at each factory. However, the company is aware of the potential of centralized planning and utilization of dynamic routes determined with help of OR methodology.
The distribution at EWOS can be described as a multi-depot vehicle routing problem with time windows, multiple vehicle usage, inter-depot routes, heterogeneous fleet and a rolling horizon. The article presents a mathematical model for the EWOS distribution problem, which is solved by heuristics and metaheuristics.