The field of stochastic scheduling is motivated by the design and operational problems arising in systems where scarce service resources must be allocated over time to jobs with random features vying for their attention. Important examples include manufacturing and computer-communication systems. Consider, e.g., the case of a manufacturing workstation processing different part types, where part...

Quality of Service (QoS) management is an important issue in today’s high-speed distributed systems supporting multimedia applications. Most existing QoS management schemes usually just cope with technical issues of resource reservations and QoS guarantees, often completely neglecting revenue issues which are especially important for service providers in order to maximize their profit. The reve...

We study server scheduling in multiclass service systems under stochastic uncertainty in the customer arrival volumes. Common practice in such systems is to first identify staffing levels, and then determine schedules for the servers that cover these targets. We propose a new stochastic integer programming model that integrates these two decisions, which can yield lower scheduling costs by expl...

in this paper, we propose a sensitivity analysis for evaluating the effectiveness of recovery solutions in the case of disturbed rail operations. indeed, when failures or breakdowns occur during daily service, new strategies have to be implemented so as to react appropriately and re-establish ordinary conditions as rapidly as possible. in this context, the use of rail simulation is vital: for e...

This essay, based on my 2012 MSOM Fellow Lecture, discusses an idea that has been useful for developing effective methods to set staffing levels in service systems: offered load analysis. The main idea is to tackle a hard problem by first seeking an insightful simplification. For capacity planning to meet uncertain exogenous demand, offered load analysis looks at the amount of capacity that wou...

This paper proposes a novel facility location model for health service network design by considering different key elements including the reliability aspects, service capacity, congestion, service quality, surrounding public infrastructures, geographical accessibility and several types of cost such as investment, transportation and operational costs. We formulate the problem as a robust scenari...

this paper presents a new formulation for warehouse inventory management in a stochastic situation. the primary source of this formulation is derived from fp model, which has been proposed by fletcher and ponnambalam for reservoir management. the new proposed mathematical model is based on the first and the second moments of storage as a stochastic variable. using this model, the expected value...

background trauma still stands atop of the list of emergencies. transfer of these patients via emergency medical services (ems) dispatch is critical with regard to importance of timing. this aspect has achieved greater importance due to population increase and telephone triage. objectives we aimed to decrease unnecessary emergency medical services (ems) missions via a computer program designed ...

background advanced ambulance service (emergency medical services/ems) is considered to be an integral part of emergency medical care as the first assets responding to emergencies and disasters in the prehospital setting in most developed countries. objectives the aim of this study was to evaluate the current situation of shiraz’s ems by comparing data obtained during two different time periods...

The performance of human resources is affected by various factors such as mental and physical fatigue, skill, and available time in the production systems. Generally, these mentioned factors have effects on human reliability and consequently change the reliability of production systems. Fatigue is a stochastic factor that changes according to other factors such as environmental conditions, work...