Vehicles Dispatching Problem for Cooperative Deliveries from Multiple Depots
Kewei Chen, Yasufumi Takama and Kaoru Hirota
Department of Computational Intelligence and Systems Science, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology Hirota Laboratory, G3 Building, Tokyo Institute of Technology 4259 Nagatsuta, Midori-Ku, Yokohama 226-8502, Japan
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 HIMS++ 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.