and holds of a vessel has fixed length whereas stockpiles can have an arbitrary length. As a consequence, the time between the completion of one task and the start of the next task (to account for any movement of equipment) can only take on a limited number of values in crane scheduling problems at a container terminal, especially in quay crane scheduling, and can take on any value in reclaimer scheduling problem.

Below, we give a brief overview of the literature on scheduling of quay and yard cranes in container terminals.

Most of the literature on quay crane scheduling focuses on a static version of the problem in which the number of vessels, berth assignments, and the quay crane assignments for each vessel are known in advance for the entire planning horizon. [@RePEc:eee:transb:v:23:y:1989:i:3:p:159-175] studies the optimal assignment quay cranes (QCs) to the holds of multiple vessels. In the considered setting, a task refers to the loading or unloading of a single hold of a vessel and any precedence constraints between the containers of a single hold are not accounted for. Crane movement time between different holds is assumed to be negligible. The fact that QCs cannot pass each other is 