Priority mode of the Entity
Queue block supports queuing in which entities positions in
the queue are based primarily on specific attribute values. Arrival
times are relevant only when attribute values are equal. You specify
the attribute and the sorting direction using the Priority
source and Sorting direction parameters
in the block dialog box.
In this example, two types of customers enter a queuing system. One type, considered to be preferred customers, are less common but require longer service. The priority queue places preferred customers ahead of nonpreferred customers. The model plots the average system time for the set of preferred customers and separately for the set of nonpreferred customers in a Dashboard Scope block.
You can see from the plots that despite the shorter service time, the average system time for the nonpreferred customers is much longer than the average system time for the preferred customers.
If the queue used a FIFO discipline for all customers instead of a priority sorting, then the average system time would decrease slightly for the nonpreferred customers and increase markedly for the preferred customers.