A supplier has a periodic review inventory system that provides several lead-time options to its customers. The inventory replenishment lead time is a multiple of the inventory review cycle. Customers are classified into two groups: short lead-time customers requiring the product immediately and long lead-time customers who allow the supplier the flexibility to deliver immediately or in the nex...

The decision of which servers to dispatch to which customers is an important aspect of serverto-customer systems. Such decisions are complicated when servers have different operating characteristics, customers are prioritized, and there are errors in assessing customer priorities. In this paper, we formulate a model for determining how to optimally dispatch distinguishable servers to prioritize...

The problem of scheduling multiple streams of realtime customers. is addressed in this paper. The paper first introduces the notion of (m, k)-firm deadlines to better characterize the timing constraints of real-time streams. More specifically, a stream is said to have (m, k)-firm deadlines if at least m out of any k consecutive customers must meet their deadlines. A stream with (m, k)-firm dead...

In the past, organisations could concentrate on their internal capabilities, emphasising product performance and technology innovation. Organisations that did not understand their customers’ needs eventually found that competitors could make inroads by offering products or services better aligned to their customers’ preferences. Many Facilities Management organisations today have a mission focu...

We ask the question, “for minimizing mean response time (sojourn time), which is preferable: one fast server of speed 1, or k slow servers each of speed 1/k?” Our setting is the M/PH/k system with two priority classes of customers, high priority and low priority, where PH is a phase-type distribution. We find that multiple slow servers are often preferable, and we demonstrate exactly how many s...

The problem of scheduling multiple streams of real-time customers is addressed in this paper. The paper rst introduces the notion of (m; k)-rm deadlines to better characterize the timing constraints of real-time streams. More speciically, a stream is said to have (m; k)-rm deadlines if at least m out of any k consecutive customers must meet their deadlines. A stream with (m; k)-rm deadlines exp...

In this paper, we study three delay systems where different classes of impatient customers arrive according to independent Poisson processes. In the first system, a single server receives two classes of customers with general service time requirements, and follows a non-preemptive priority policy in serving them. Both classes of customers abandon the system when their exponentially distributed ...

We consider Markovian multi-server queues with two types of impatient customers: highand low-priority ones. The first type of customers has a non-preemptive priority over the other type. After entering the queue, a customer will wait a random length of time for service to begin. If service has not begun by this time he or she will abandon and be lost. We consider two cases where the discipline ...