Split Queue Rules

SPT*   Two queues prioritized as per to SPT. The operations for that t_sj - u is negative form a high priority queue that is processed first. The order inside the two queues is as per to the SPT-rule. u is a design parameter that defines while an operation becomes urgent.

SPT/SL similar as SPT* except which the high priority queue is ordered as per to SL instead of SPT.

CEXSPT Three queues are considered opposite each station. The initial queue contains the operations   along with   negative   slack   t_sj     (previously   delayed,   tardiness inevitable), the second those along with negative local slack (operation due date has passed), and the third the keeping (uncritical) operations. Each queue is prioritized as per to SPT. The initial queue has the highest priority. Conversely, operations from this queue are merely scheduled, whether none of the staying operations would have negative slack subsequently. Operations from the second queue are merely scheduled, whether none of the remaining operations would have negative slack afterwards. Operations from the second queue are merely scheduled whether no operation from the third queue would have a negative slack afterwards.

 Throughput-oriented Rules

• WINQ (smallest work in next queue)
• COVERT (cost over time) Decision based upon an estimation of the waiting time in the next queues.