the port takes a considerable amount of time. Once the assembly of a stockpile has started, it is rare that the location of the stockpile in the stockyard is changed; relocating a stockpile is time-consuming and requires resources that can be used to assemble or reclaim other stockpiles. Thus, deciding where to locate a stockpile and when to start its assembly is critical for the efficiency of the system. Ideally, the assembly of the stockpiles for a vessel completes at the time the vessel arrives at a berth (i.e., “just-in-time” assembly) and the reclaiming of the stockpiles commences immediately. Unfortunately, this does not always happen due to the limited capacities of the resources in the system, e.g., stockyard space, stackers, and reclaimers, and the complexity of the stockyard planning problem.

A seemingly small, but in fact crucial component of the planning process is the scheduling of the reclaimers, because reclaimers tend to be the constraining entities in a coal terminal (the reclaiming capacity is substantially lower than the stacking capacity).

The characteristics of the reclaimer scheduling problems studied in this paper are motivated by those encountered at a stockyard at one of the cargo assembly terminals at the Port of 