E. Lerzan Örmeci

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We study a class of queueing control problems involving commonly used control mechanisms such as admission control, pricing, and service rate control. Such controls are frequently employed in modeling service systems, telecommunications , and also in inventory systems modeled as make-to-stock queues. It is by now well established that in a number of such(More)
The purpose of this paper is to investigate the structural properties of the optimal batch acceptance policy in a Markovian queueing system where different classes of customers arrive in batches and the buffer capacity is finite. We prove that the optimal policy can possess certain monotonicity properties under the assumptions of a single-server and(More)
Calls of two classes arrive at a call center according to two independent Poisson processes. The center has two dedicated stations, one for each class, and one shared station. All three stations consist of parallel servers and no waiting room. Calls of each type demand exponential service times with different service rates and generate different rewards.(More)
This paper investigates an optimal sequencing and dynamic pricing problem for a two-class queueing system. Using a Markov Decision Process based model, we obtain structural characterizations of optimal policies. In particular, it is shown that the optimal pricing policy depends on the entire queue length vector but some monotonicity results prevail as the(More)
Keywords: OR in health services Transportation Logistics of clinical testing laboratories a b s t r a c t We study the logistics of specimen collection for a clinical testing laboratory that serves sites dispersed in an urban area. The specimens that accumulate at the customer sites throughout the working day are transported to the laboratory for(More)
We study the effects of different pricing strategies available to a continuous review inventory system with capacitated supply, which operates in a fluctuating environment. The system has a single server with exponential processing time. The inventory holding cost is nonde-creasing and convex in the inventory level, the production cost is linear with no(More)
We investigate the structural properties of a finite horizon, discrete time single product inventory rationing problem, where we allow random replenishment (production) opportunities. In contrast to the standard models of dynamic capacity control in revenue management or production/inventory systems, we assume that the demand/production rates are not known(More)