普通顾客排队且排队顾客优先的混合排队问题?

为了解决通信信道资源管理中的网络优化问题,本文将普通的 M/M/n/N/∞排队模型推广为两类顾客到达的混合排队模型.其中共有有限个服务台和一个长度有限的等待区,一部分服务台为普通顾客和特殊顾客共用,剩余的服务台预留给特殊顾客使用,等待区专供普通顾客排队使用,排队顾客只接受共用的服务台的服务,两类顾客均为泊松到达.我们应用差分方程,得出了稳态时模型中各状态的概率分布.     

考虑顾客耐心的呼叫中心等待提示决策模型

通过向客户提示可能需要等待的排队时间来改善顾客满意度是目前呼叫中心的重要手段之一。实践表明,提示时间长短的确定对顾客满意度和呼叫中心效用具有重要影响作用。基于排队论建立了考虑顾客心理行为影响的最大系统效用优化模型,并给出了基于混沌搜索的求解算法。针对一类带有排队等待时间提示的M/M/N+M排队模型,研究了排队时间提示对顾客耐心心理与放弃行为的影响规律,用概率函数描述了顾客心理变化和放弃行为,推导了稳态下的排队系统的性能计算公式,构建了最大化系统效用值的优化模型和混沌搜索求解算法。数值实验验证了算法的收敛性和有效性,并给出了不同耐心顾客群体和呼叫中心运营模式下的系统最优提示时间策略和效用值的变化规律,作为实际工作中的指导准则。     

具有阀值策略的M/M/2/K多重休假排队系统

本文研究了带有阀值策略的服务器不同的M/M/2/K异步多重休假排队系统.第一个服务器在服务完一个顾客后,若发现系统中无等待的顾客,则立刻开始休假.当系统中等待的顾客数小于阀值时,第二个服务器开始休假.论文通过深入研究该系统的性能,为决策者提供一些参考.利用矩阵分析的方法,求出了系统的平稳概率向量和排队指标的解析表达式.最后,我们构造了一个费用模型,并分析了各参数对系统最小费用和最优阀值的影响.     

两类排队网络的逼近研究

本文给出了两类排队网络。一类是容量有限的队列网络,我们证明了在高负荷下,标准化的队长过程弱收敛于半鞅反射的布朗运动：另一类是带有反馈的多类顾客多服务台队列网络,我们获得了队列网络中负荷过程的扩散逼近。     

基于马尔可夫的串联呼叫中心系统建模与工作分配策略研究

对一类具有"前台接入,后台拨出"特征的串联呼叫中心前后台工作内容再分配问题进行了建模研究,应用服务速率集成近似的马尔可夫性能解析算法,探讨了面向再分配结果的优化策略。首先在集成近似的基础上采用矩阵几何求解了某一金融业务电话咨询系统中顾客的平均等待队长、服务台利用率等主要系统性能指标,并使用Arena仿真验证了服务速率集成近似方法的准确性。其次,应用了优化算法从系统整体经济损失最小化的角度探究了最优工作再分配策略,并验证了优化算法的有效性和适用性,为这类特殊呼叫中心的性能优化问题提供了决策参考和理论依据。     

卓越绩效标准透视——以顾客和市场为中心(I)

《卓越绩效标准》第3类目为“以顾客和市场为中心”。其中包括“3郾1了解顾客和市场”、“3郾2顾客关系与顾客满意”两个条目。一、以顾客和市场为中心这一类目的要求反映了卓越绩效标准的视角——顾客驱动的卓越,表明了在当今飞速发展和激烈竞争的市场环境中,企业经营的基本立场和出发点。该类目审查组织如何确定顾客和市场的要求、期望和偏好,以及如何与顾客建立关系,如何确定决定着顾客的获得、满意、忠诚、保持以及业务扩展的那些关键因素。它要求说明组织如何寻求了解顾客和市场的声音,满足顾客的期望和要求,以取悦顾客、建立顾客忠诚…     

基于服务环境的顾客密集型服务研究

顾客密集型服务中,更耐心的服务容易造成服务队列的拥挤,但优质的服务环境能够有效地减少顾客等待过程中内心的焦躁,同时也会增加服务商成本。基于M/M/1模型,分析服务环境对顾客等待过程中产生的影响以及服务商关于服务环境水平、服务速率和服务价格的最优决策。研究发现,处于发展初期的服务商需要更重视服务环境的营造,更注重“质量竞争”;当市场需求超过某一阈值后,服务环境对顾客的购买决策影响力降低,服务商需要通过更低的价格去占据更大的市场份额,为总体利润寻求更大的上涨空间。     

高负荷下G/G/n/mn+G队列的等待时间?

本文对多个服务台、带有顾客放弃和等待空间的G/G/n/mn+G队列模型,在高负荷下的等待时间的随机过程极限进行了研究。应用二维Puhalskii的首达时间的不变性定理,在队列模型在某一时刻之后顾客停止到达系统的条件下,得到了队列模型在高负荷下的等待时间的随机过程极限。     

物流企业配送系统的顾客满意度测评

为解决物流配送中满意度因素过多问题和进行有效的满意度水平测评,利用灰色关联分析和灰色关联聚类筛选出具有代表性的满意度指标,结合正三角模糊理论建立了完善的物流企业配送系统顾客满意度测评模型,最后对桂林某物流公司配送系统进行了客户满意度测评,结果对企业改善顾客满意度指出了方向.     

带有假期延迟服务台不稳定的闸门服务M/G/1排队系统分析(英文)北大核心CSCD

在本文中,我们推广了带有休假的服务台不稳定的闸门服务M/G/1排队模型.当一个假期结束时,服务台发现系统为空,则服务台将启动一个随机长度的闲期.如果在闲期内有顾客到达,则服务台立即为该顾客服务;否则,当闲期结束后服务台不再等待而是接续另一个假期.在服务期的任何时间内服务台都有可能发生毁坏,毁坏到达是一个Possion过程,服务台的维修时间服从一般分布.在关于M/G/1排队系统现有结果的基础上,通过概率分析,应用母函数和LST得出了稳态下队长和等待时间的随机分解公式以及平均队长和平均等待时间.     

Finite waiting space bulk queueing systems

Summary This paper extends earlier work on the stationary queue length distribution of a bulk service system with finite waiting space by considering two queueing systems. The first system incorporates the feature of batch arrivals with group service; it has compound Poisson input, general service times and a single server with variable batch capacity. The second system has individually arriving customers with Erlangian interarrival time distribution, general service times and a single server with variable batch capacity.The financial support of the National Research Council of Canada, under Research Grants No. 3-644-189-60; NRC-A5639 and No. 3-641-189-10; NRC-A2796, is acknowledged.     

Analysis of finite-buffer state-dependent bulk queues

In this paper, we consider a general state-dependent finite-buffer bulk queue in which the rates and batch sizes of arrivals and services are allowed to depend on the number of customers in queue and service batch sizes. Such queueing systems have rich applications in manufacturing, service operations, computer and telecommunication systems. Interesting examples include batch oven processes in the aircraft and semiconductor industry; serving of passengers by elevators, shuttle buses, and ferries; and congestion control mechanisms to regulate transmission rates in packet-switched communication networks. We develop a unifying method to study the performance of this general class of finite-buffer state-dependent bulk queueing systems. For this purpose, we use semi-regenerative analysis to develop a numerically stable method for calculating the limiting probability distribution of the queue length process. Based on the limiting probabilities, we present various performance measures for evaluating admission control and batch service policies, such as the loss probability for an arriving group of customers and for individual customers within a group. We demonstrate our method by means of numerical examples.     

带有止步和中途退出的M/M/1/N多重休假排队系统的等待时间

本文研究了带有止步和中途退出的多重休假排队系统模型,该排队模型的稳态概率已在我们的另一篇文章中给出.本文的目的是在稳态概率的基础上推导系统的稳态等待时间分布.通过对进入系统的顾客可能中途退出的不同情况的概率分析,我们分别在服务员忙和休假的情况下得到了进入系统并接受服务的顾客的稳态条件等待时间分布,进而得到了进入系统并接受服务的顾客的稳态条件等待时间的概率密度.     

Blocking Probabilities for a Class of Two-Station Tandem Queueing Models

We study a two-station tandem queueing system with a finite buffer of maximum size M (M≥0) between the stations. The first service station has L≥1(homogeneous) parallel servers with an unlimited waiting space, while at the second there are N≥1 (homogeneous) parallel servers. Assuming Poisson arrivals and exponential service times, we derive exact results for the blocking probabilities for some special cases, and we present a unified approach for the analysis of this class of models under saturation conditions. Practical applications of the model are also discussed.     

Coping with production time variability via dynamic lead-time quotation

In this paper, we propose two dynamic lead-time quotation policies in an M/GI/1 type make-to-stock queueing system serving lead-time sensitive customers with a single type of product. Incorporating non-exponential service times in an exact method for make-to-stock queues is usually deemed difficult. Our analysis of the proposed policies is exact and requires the numerical inversion of the Laplace transform of the sojourn time of an order to be placed. The first policy assures that the long-run probability of delivering the product within the quoted lead-time is the same for all backlogged customers. The second policy is a refinement of the first which improves the profitability if customers are oversensitive to even short delays in delivery. Numerical results show that both policies perform close to the optimal policy that was characterized only for exponential service times. The new insight gained is that the worsening impact of the production time variability, which is felt significantly in systems accepting all customers by quoting zero lead times, decreases when dynamic lead-time quotation policies are employed.     

一类Kelly-型排队网络的稳定性

排队网络可以用来模拟诸如通信网络这样的复杂系统。对排队网络的研究中的一个主要议题是建立其在某些特殊的规则下稳定的充要条件。本文的研究对象是一类具有两类顾客输入的Kelly-型排队网络。利用流体模型以及Lyapunov函数等工具,建立了该排队网络在所有非闲置的规则下稳定的充分条件。最后,对条件的充分性作了说明。     

多服务速率多重休假M/G(M/G)/1可修排队

本文通过对系统中顾客数设置门限N,考虑研究了服务台的服务速度依门限发生变化且当服务台未服务顾客(休假或故障)时到达顾客仅以概牢p进入系统的多重休假可修M／G(M／G)／1排队系统。通过L-变换、母函数以及补充变量方法得到了队长分布的瞬态解、稳态解及一些可靠性结果,并指出当两个服务速度相等时该模型与前人研究的M／G／1(E,MV）排队一致。     

A discrete-time queueing network approach to performance evaluation of autonomous vehicle storage and retrieval systems

In this paper, we present a method for performance evaluation of autonomous vehicle storage and retrieval systems (AVS/RSs) with tier-captive single-aisle vehicles. A discrete-time open queueing network approach is applied. The data obtained from the evaluation of the lift and vehicle movements can be used directly as input for the general discrete service time distributions of the queueing network. Furthermore, the approach allows for the computation of the retrieval transaction time distribution as well as of the distribution of the number of transactions waiting to be stored. Consequently, not only expected values and variances but also quantiles of the performance measures can be obtained. Comparison to discrete-event simulation quantifies approximation errors resulting from the decomposition approach in the discrete-time domain. Moreover, the errors obtained by the discrete-time approach are compared to the errors obtained using a continuous-time open queueing network approach. Finally, it will be outlined how the model can be used for designing AVS/RSs according to given system requirements, such as storage capacity, throughput, height and length of the system as well as the 95% quantile of the retrieval transaction time.     

Single server queues with restricted accessibility

Summary A queueing system has restricted accessibility if not every customer is admitted to the system. For such a system the admittance of a customer will in general depend on the state of the queueing system at the moment of his arrival. In this paper queueing models will be studied for which the accessibility depends on the actual waiting time of the arriving customer. Various queueing situations encountered in the allocation of memory equipment for information processing systems may be described as a single server queueing system with restricted accessibility; the mathematical models for the involved storage problems belong to queueing theory and are discussed in the present paper.     

Priority Loss Systems—Unequal Holding Times

This paper considers the following queueing system:; two classes of customers use the same s-server loss system. A mathematical model is developed for the case where one class of customer can preempt the other and the mean service times of each class of customer may be different. These results are then used to numerically investigate the behavior of various measures of performance as well as the system in general.