This paper aims to analyze the variation in the delivery of diagnostic imaging services in order to suggest possible solutions for the reduction of waiting times, increase the quality of services and reduce financial costs. Design: This study provides a logic model to manage waiting times in a...

We present a Markov model to approximate the queueing behavior at the G(t)/G(t)/s(t)+G(t) queue with exhaustive discipline and abandonments. The performance measures of interest are: (1) the average number of customers in queue, (2) the variance of the number of customers in queue, (3) the...

Comprehensive long term maintenance contracts are a recent trend in equipment industries. At the same time increasing environmental concerns and high prices for raw materials stress the importance of remanufacturing activities. Hence, maintenance contracts often result in remanufacturing of some...

Consider the following due-date scheduling problem in a multiclass, acyclic, single-station service system: any class k job arriving at time t must be served by its due date t D_{k}. Equivalently, its delay ¦Ó_{k} must not exceed a given delay or lead-time D_{k}. In a stochastic system the...

We study how multi-product queueing systems should be controlled so that sojourn times (or end-to-end delays) do not exceed specified leadtimes. The network dynamically decides when to admit new arrivals and how to sequence the jobs in the system. To analyze this difficult problem, we propose an...

Long queues in seasonal sales shopping are seemingly undesirable for shoppers and retailers. Yet, this paper proposes that shoppers' impatience can be a virtue for retailers. It shows that, when shoppers do queue, it is desirable under some conditions for retailers to strategically keep the...

In this Extended Appendix, we extend the mixed integer second-order cone programming (MISOCP) formulation as well as the heuristics derived in Mak et al. (2013) to tackle the problem of assigning and sequencing appointments for multiple servers. Numerical examples are provided to demonstrate the...

We study a closed, three-station queuing network with general service time distributions and balanced workloads (that is, each station has the same relative traffic intensity). If the customer population is large, then the queue length process of such a network can be approximated by driftless...

This paper studies the operating characteristics of an MX/Hk/1 queueing system under multiple vacation policy. It is assumed that the server goes for vacation as soon as the system becomes empty. When he returns from a vacation and there is one or more customers waiting in the queue, he serves...