The sequence priority establishes the manner in which machines are selected for loading and unloading.Machines with a sequence priority of zero will rotate priority according to how long the machines have been waiting to load or unload.
Machines with a sequence priority greater than zero attain a higher priority of selection than those units with a sequence priority of zero.
A sequence Priority of 1 is the highest priority.
The available machine with the smallest non-zero priority will be selected preferentially.
Machines with the same priority will be handled in a shortest path algorithm, meaning that the machine closest to the current position of the shuttle or the first machine in a rail queue will be handled first.