Design and Evaluation of COBALT Queue Discipline

Objectives: Potential problems concerning waiting list management are often monitored using mean waiting times based on empirical samples. However, the appropriateness of mean waiting time as an indicator of access can be questioned if a waiting list is not managed well, e.g., if the queue discipline is violated. This study was performed to find out about the queue discipline in waiting lists for elective surgery to reveal potential discrepancies in waiting list management. Methods: There were 1,774 waiting list patients for hallux valgus or varicose vein surgery or sterilization. The waiting time distributions of patients receiving surgery and of patients still waiting for an operation are presented in column charts. The charts are compared with two model charts. One model chart presents a high queue discipline (first in—first out) and another a poor queue discipline (random) queue. Results: There were significant differences in waiting list management across hospitals and patient categories. Examples of a poor queue discipline were found in queues for hallux valgus and varicose vein operations. Conclusions: A routine waiting list reporting should be used to guarantee the quality of waiting list management and to pinpoint potential problems in access. It is important to monitor not only the number of patients in the waiting list but also the queue discipline and the balance between demand and supply of surgical services. The purpose for this type of reporting is to ensure that the priority setting made at health policy level also works in practise.

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The single-server queue with service depending on queue size and with the preemptive-resume last-come–first-served queue discipline

Journal of Applied Probability ◽

10.1017/s0021900200031466 ◽

1987 ◽

Vol 24 (03) ◽

pp. 758-767

Author(s):

D. Fakinos

Keyword(s):

Queueing System ◽

Limiting Distribution ◽

Single Server ◽

Queue Size ◽

Single Server Queue ◽

Preemptive Resume ◽

Server Queue ◽

Queue Discipline ◽

Service Times

This paper studies theGI/G/1 queueing system assuming that customers have service times depending on the queue size and also that they are served in accordance with the preemptive-resume last-come–first-served queue discipline. Expressions are given for the limiting distribution of the queue size and the remaining durations of the corresponding services, when the system is considered at arrival epochs, at departure epochs and continuously in time. Also these results are applied to some particular cases of the above queueing system.

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The truncated Hyper-Poisson queues: Hk/Ma,b/C/N with balking, reneging and general bulk service rule

Yugoslav journal of operations research ◽

10.2298/yjor0801023s ◽

2008 ◽

Vol 18 (1) ◽

pp. 23-36 ◽

Cited By ~ 1

Author(s):

A.I. Shawky ◽

M.S. El-Paoumy

Keyword(s):

Steady State ◽

Analytical Solution ◽

Explicit Form ◽

Recurrence Relations ◽

Expected Number ◽

Special Cases ◽

Queue Discipline ◽

Bulk Service ◽

General Bulk Service Rule ◽

Steady State Probabilities

The aim of this paper is to derive the analytical solution of the queue: Hk/Ma,b/C/N with balking and reneging in which (I) units arrive according to a hyper-Poisson distribution with k independent branches, (II) the queue discipline is FIFO; and (III) the units are served in batches according to a general bulk service rule. The steady-state probabilities, recurrence relations connecting various probabilities introduced are found and the expected number of units in the queue is derived in an explicit form. Also, some special cases are obtained. .

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Control of the Queue Discipline

Fuzzy Control of Queuing Systems ◽

10.1007/1-84628-073-7_5 ◽

2005 ◽

pp. 69-93

Keyword(s):

Queue Discipline

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Stationary waiting-time distributions in the GI/PH/1 queue

Journal of Applied Probability ◽

10.2307/3213064 ◽

1981 ◽

Vol 18 (4) ◽

pp. 901-912 ◽

Cited By ~ 10

Author(s):

Marcel F. Neuts

Keyword(s):

Waiting Time ◽

Embedded Markov Chain ◽

Asymptotic Results ◽

Waiting Time Distributions ◽

Structured Systems ◽

Queue Discipline ◽

The Matrix ◽

Constant Coefficients ◽

Linear Differential ◽

Stationary Waiting Time

It is known that the stable GI/PH/1 queue has an embedded Markov chain whose invariant probability vector is matrix-geometric with a rate matrix R. In terms of the matrix R, the stationary waiting-time distributions at arrivals, at an arbitrary time point and until the customer's departure may be evaluated by solving finite, highly structured systems of linear differential equations with constant coefficients. Asymptotic results, useful in truncating the computations, are also obtained. The queue discipline is first-come, first-served.

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