We study a chemical tanker scheduling problem in which a multi-compartment chemical tanker picks up chemicals (within specific time windows) and delivers them to their destinations. Additional safety and ship balancing requirements related to the compartment storage need to be met. We refer to this problem as the single ship pick-up and delivery problem with pick-up time windows, tank allocations and changeovers (s-PDP-TWTAC). We propose a formulation for the s-PDP-TWTAC that is significantly smaller in size when compared to the existing approaches. Even though our formulation requires significantly lesser computational effort than others, it is still challenging to solve for large realistic networks. We propose a linear programming based neighbourhood search heuristic to find good solutions to these problems. We also describe an instance generator for creating random but realistic instances, and a library of instances that have been created for testing and benchmarking.

我们研究了一个化学品运输船的调度问题，其中一个多室化学品运输船（在特定的时间范围内）拾取化学品并将其运送到目的地。需要满足与隔间存储相关的其他安全和船舶平衡要求。我们将此问题称为具有拾取时间窗口，油箱分配和转换的单船拾取和交付问题（s-PDP-TWTAC）。我们为s-PDP-TWTAC提出了一种配方，与现有方法相比，其尺寸要小得多。即使我们的公式比其他公式所需的计算量少得多，但解决大型现实网络仍然具有挑战性。我们提出了一种基于线性规划的邻域搜索启发式算法，以找到针对这些问题的良好解决方案。我们还将描述用于创建随机但现实的实例的实例生成器，以及已创建用于测试和基准测试的实例库。