Simultaneous Scheduling and Routing of Pipeless Plants in Different Layouts

In this work, simultaneous scheduling and vessel routing problem of pipeless plants is addressed with different layouts of units/stations. A general framework is presented for optimization of pipeless plants, which includes guidelines for state-task-network development covering issues such as when to consider vessels as states and how to handle vessel routing. The proposed formulation has been illustrated using two case studies drawn from the literature. For the demonstration of the proposed simultaneous approach, three different layouts: linear, herringbone, and circular, are considered in example 1 with three vessels. The herringbone layout results in better makespan value, as expected. The second case study is relatively large with six vessels and is solved for the herringbone layout for the different number of vessels.