Improved Discrete Time Model for Container Yard Crane Scheduling

Yard crane is expensive and slow so that it has become a bottleneck in container terminal. The scheduling models and algorithms for yard cranes have attracted some scholars. The recently published achievement has considered the inter-crane interference, yard crane separation distances and simultaneous container storage and retrieval. However, due to the complexity and the scale, the mathematical model is difficult to be solved by commercial operation software packages. Heuristic algorithm seems to be the only solution. In this study, the problem with such features is reformulated to be a discrete time model with less variables and simpler constraints so that the model can be solved by commercial operational software package directly and efficiently.