Vehicles Dispatching Problem for Cooperative Deliveries from Multiple Depots

A new concept of the VDP/CD/MD problem (Vehicles Dispatching Problem for Cooperative Deliveries from Multiple Depots) and its formularization are proposed to provide a solver for the complex situation in the real new style transportation problem. An enhanced computational model with hierarchical multiplex structure, called the HI MS" model, is introduced for the VDP/CD/MD problem. It contains 3 layers: the Atomic layer is a fluctuation area of system cost, the Molecular layer is a forming area of system state, and the Individual layer is a decision area of dispatching plan. The HIMS⁺⁺ model is constructed as a software component using object-oriented paradigm. Its optimization algorithm is implemented through meta-heuristic and fuzzy inference methods. Experiments using 3-day order data taken from an actual dispatching center in Tokyo metropolitan area with 27 tank lorries (2 types) are done. It is confirmed that the HIMS⁺⁺ model is very accurate (10% up) and fast (12 times) than the results given by the experts. The HIMS⁺⁺ model is also a convenient tool (with few parameters and covering many objectives) for practical transportation problems.