Two‐tier healthcare service systems and cost of waiting for patients

Waiting has been a significant concern for healthcare services. We address this issue in the context of a two‐tier service system in this study. A two‐tier healthcare service system consists of two different service providers, typically one public service provider and one private service provider. In a baseline model, the two service providers are modeled by two queue servers, which charge each patient a common fixed fee for the service. Then, we study a queue model in which one service provider offers a subsidy or charges a premium while the other maintains the fixed service fee. This system provides a mechanism to segment patients along their waiting time cost through price discrimination. We analyze the problem from both the perspective of minimizing total waiting cost for all patients and the perspective of maximizing social gain for the public service provider or profit for the private service provider. We show that this model can significantly alleviate the burden of waiting for patients. The study addresses the design, the efficiency, and the implementation of two‐tier healthcare service systems. Copyright © 2017 John Wiley & Sons, Ltd.     

A simple load balancing problem with decentralized information

The following load balancing problem is investigated in discrete time: A service system consists of two service stations and two controllers, one in front of each station. The service stations provide the same service with identical service time distributions and identical waiting costs. Customers requiring service arrive at a controller's site and are routed to one of the two stations by the controller. The processes describing the two arrival streams are identical. Each controller has perfect knowledge of the workload in its own station and receives information about the other station's workload with one unit of delay. The controllers' routing strategies that minimize the customers' total flowtime are determined for a certain range of the parameters that describe the arrival process and the service distribution. Specifically, we prove that optimal routing strategies are characterized by thresholds that are either precisely specified or take one of two possible values.     

考虑双边服务水平的网购服务供应链协调契约

本文考虑了由单个网络商店和单个第三方物流企业(TPL)所构成的二级网购服务供应链,在双方服务水平同时影响市场需求的情况下,研究了网购服务供应链的服务质量协调问题。通过对比分散式和集中式供应链中各方的均衡决策,指出传统价格契约的不足,提出采用收益共享契约对供应链进行协调,并分析了该契约实现供应链协调的条件和局限。研究结果表明:收益共享契约能激励双方提高服务水平、实现供应链协调;协调契约实施前后各方的基本服务水平对各自的收益和服务决策均有正向影响,且相应的影响在协调契约下更明显。此外,研究还指出供应链系统可能会因TPL服务能力不足发生服务拥塞,使得系统运营效率降低。最后,通过算例验证了收益共享契约的有效性,并对主要参数的灵敏度进行了分析。     

考虑加工速率相互干扰的平行机调度最优策略研究

随着智能互联网的应用深入、个性化消费时代的来临,制造服务企业开始注重利用网络平台为客户提供个性化的定制服务,在此过程中派生出了产品设计师可与多名客户在线同步交互的一种新型服务模式。本文根据设计师服务效率受并行服务客户数量影响的特征,将问题刻画为机器处理速度相互影响的一类平行机调度模型,以最小化总完工时间为优化目标,研究设计最优调度方案。首先,对于只有两名设计师且各自同时处理最多两个任务的情形,提出了改进的SPT调度规则,运用归纳法证明了该规则可以生成最优加工方案。其次,对改进的SPT规则进行任务分配方式的适当松驰以便更加易于操作,并证明松驰后的新分配方案保持了解的最优性。最后,将相关结论推广至多名设计师的一般情形。上述研究为个性化在线定制服务模式下的有效调度策略制定提供了良好的理论支撑。     

竞争平台的增值服务投资均衡策略

本文以两个竞争平台为研究对象,考虑消费者异质性和网络外部性下服务平台是否提供增值服务,分别构建了两个平台均提供/不提供增值服务(PP/SS)和仅一个平台提供增值服务(PS)三种情景下的收益模型,求解出各情景的最优价格、服务水平和收益,并探讨了竞争平台的增值服务投资均衡策略。研究发现：(1)若平台的服务提供者数量很低时,两个平台均会提供增值服务;随着服务提供者数量的增加,仅一个平台提供增值服务(PS/SP)是均衡。(2)平台服务提供者数量的增加会削弱增值服务的利润增长优势。此外,当平台的基本服务价值低于某一阈值时,服务提供者数量较高的平台不会提供增值服务;当基本服务价值高于某一阈值时,该平台会提供增值服务。     

基于排队系统的偏好差异性顾客服务策略分析

在服务商为不同偏好顾客提供差异性服务的排队系统中,其收益受到需求规模、顾客类型等因素影响,如何制定策略才能达到服务特定类型顾客并获取最大收益的目的？本文以服务时间与效果正相关的顾客密集型服务为背景,基于M/M/1模型对服务商为两种偏好顾客提供两种服务的情景进行研究,并将从偏好服务所获基准效用相对较低、较高的顾客分别定义为1类、2类顾客。结果表明,①随着潜在顾客规模的增加,最优策略所适用的3种基本策略依次为公平策略、优先服务2类顾客的策略以及仅服务2类顾客的排他性策略;②3种基本策略的适用范围仅与1类顾客的服务选择标准相关;③在优先服务某类顾客的策略中,有效到达速率及服务速度由另一类顾客的特征决定。     

考虑公平关切的O2O模式下物流服务供应链定价策略博弈分析

针对两个物流服务提供商(FLSP)和单个物流服务集成商自营的线上物流平台(LSIO)组成的两层O2O模式下物流服务供应链,即考虑物流服务集成商(LSI)自营线上物流平台的情形,将公平关切引入到O2O模式下物流服务供应链的定价决策中,基于Stackelberg博弈模型,研究物流服务提供商(FLSP)的公平关切有限理性行为对物流服务供应链成员定价策略和效用的影响。研究结论表明:在仅考虑横向公平关切和考虑双向公平关切这两种情形下,后进入市场的物流服务提供商(FLSP2)都应控制自己的横向公平关切行为,否则会影响O2O模式下物流服务供应链的发展;在考虑双向公平关切的情形下,先进入市场的物流服务提供商(FLSP1)发现分配给自己的物流服务订单量减少后,FLSP1会对LSIO产生纵向不公平厌恶,而FLSP1的纵向公平关切程度达到一定水平后,物流服务集成商自营的线上物流平台(LSIO)应重视 FLSP1的纵向公平关切,避免物流服务提供商流失。     

Strategic interactions in service supply chain with horizontal competition

We analyze strategic interaction issues that arise in service supply chain, such as consulting, service outsourcing, and travel service. To capture strategic interactions in service supply chain, we study a case where there are two service vendors providing competing service products and selling them through a common Service Integrator. In particular, we derive and compare equilibrium solutions (e.g. service prices, wholesale prices, service volumes) for the service supply chain under three different scenarios. We then study the effect of key parameters in the model upon the equilibrium solution using sensitivity analysis, and discuss our results along with a numerical experiment. Finally, future research direction is pointed out.     

A Tandem Queue with a Gate Mechanism

Inspired by a problem regarding cable access networks, we consider a two station tandem queue with Poisson arrivals. At station 1 we operate a gate mechanism, leading to batch arrivals at station 2. Upon arrival at station 1, customers join a queue in front of a gate. Whenever all customers present at the service area of station 1 have received service, the gate before as well as a gate behind the service facility open. Customers leave the service area and enter station 2 (as a batch), while all customers waiting at the gate in front of station 1 are admitted into the service area. For station 1 we analyse the batch size and the time between two successive gate openings, as well as waiting and sojourn times of individual customers for different service disciplines. For station 2, we investigate waiting times of batch customers, where we allow that service times may depend on the size of the batch and also on the interarrival time. In the analysis we use Wiener–Hopf factorization techniques for Markov modulated random walks.     

基于分类服务机制的可预约排队系统设计和服务定价研究

采取合理有效的服务机制和服务定价是确保服务型企业持续有效运行的重要方式,服务提供商设计合理的服务策略可以使得服务收益达到最优。本文以服务可预约的排队系统为研究背景,对服务提供商分类服务机制选择和服务定价策略进行研究。通过考虑由两种服务策略下顾客之间的平均等待时间的对比和顾客等待厌恶心理参数形成的全新顾客服务效用模型,给出服务提供商在不同服务机制下的最优服务策略以及顾客市场规模对其服务策略选择的影响。研究表明,当预约顾客的市场规模相对较小时,服务提供商可以采取分类服务机制,即同时服务预约顾客和未预约顾客以增加服务收益,反之亦然。此外,预约顾客等待厌恶程度能够显著增大服务提供商的服务定价。     

Game theoretic modelling of service agent warranty fraud

When a warranty provider outsources warranty servicing to an external service agent this agent may act in a fraudulent manner. In this paper we consider a special case of service agent fraud—with the service agent overbilling the warranty provider for some of the warranty claims. A detailed inspection of a claim may be made to identify whether or not the service agent has committed fraud, but this inspection involves an additional cost to the warranty provider. This cost may be recovered by imposing a penalty on the service agent whenever a fraud is committed and it is detected. This penalty is specified in the maintenance service contract. A game theoretic approach is used to find the optimal overbilling strategy for the service agent and the optimal inspection strategy for the warranty provider. The optimal solution is the mixed strategy Nash equilibrium of a static game between the two parties.     

公平关切下物流服务供应链质量缺陷承诺策略研究

考虑物流服务供应链中成员的公平关切行为,以Nash讨价还价均衡解作为公平收益参照点,构建Nash讨价还价公平关切下物流服务供应链质量缺陷承诺策略模型,分析和研究公平关切对最优策略、利润和效用的影响。研究结果表明,物流服务质量缺陷承诺水平随着物流服务集成商公平关切系数的增加而减少,却随着物流服务提供商公平关切系数的增加而增加;物流服务订购量随着物流服务集成商公平关切系数的增加而减少,也随着物流服务提供商公平关切系数的增加而减少;当物流服务提供商的公平关切系数增加时,物流服务供应链中各成员的利润和效用以及整体利润和效用都会不断减少;但当物流服务提供商的公平关切程度一定而物流服务集成商的公平关切系数增加时,物流服务供应链中各成员的利润和效用以及整体利润和效用不断提高。     

Operational effects of service level variations for the dial-a-ride problem

The dial-a-ride problem consists of designing a number of minimum-cost vehicle routes in a system of demand-dependent, collective people transportation. Quality is ensured by taking into account service level requirements. However, little research has been conducted into the effect of service level variations on operational costs incurred by service providers. This study investigates the evolution of operational costs for 78 combinations of two service level parameters, being the maximum deviation from a user’s preference time and the relative maximum exceedance of a user’s direct ride time. A distinction is made between various operating circumstances, including the size of the service provider, the traffic conditions in the service area and the heterogeneity of the customers. The resulting tradeoffs between quality and costs should encourage service providers to make informed decisions regarding potential changes in the service level they offer. The sensitivity analysis in this paper is performed on well-known benchmark data from literature and applies a state-of-the-art deterministic annealing metaheuristic to compute operational costs.     

On Queues with Markov Modulated Service Rates

In this paper, we consider a queue whose service speed changes according to an external environment that is governed by a Markov process. It is possible that the server changes its service speed many times while serving a customer. We derive first and second moments of the service time of customers in system using first step analysis to obtain an insight on the service process. In fact, we obtain an intriguing result in that the moments of service time actually depend on the arrival process! We also show that the mean service rate is not the reciprocal of the mean service time. Further, since it is not possible to obtain a closed form expression for the queue length distribution, we use matrix geometric methods to compute performance measures such as average queue length and waiting time. We apply the method of large deviations to obtain tail distributions of the workload in the queue using the concept of effective bandwidth. We present two applications in computer systems: (1) Web server with multi-class requests and (2) CPU with multiple processes. We illustrate the analysis and various methods discussed with the help of numerical examples for the above two applications. AMS subject classification: 90B22, 68M20     

Inventory control by different service levels

This paper examines the multiple period inventory control problem of a single product with multiple (two) prices, depending on service level, in which optimal pricing and ordering decisions are made in each period. Traditional inventory and pricing models consider only single products, single prices, and single service levels. However, this research paper finds that a seller can improve inventory control and revenue by offering multiple prices depending on service level. This research considers a single product with multiple (two) pricing policies corresponding to service level as follows: if the customer is willing to delay the shipment, he/she will be offered a lower regular price. Otherwise, the customer will pay the regular price plus extra charges for express service. In this paper, I show the following: (1) there is an optimal pricing and replenishment policy that can control inventory and (2) there exists a finite threshold for inventory levels such that if the inventory level at the beginning of each period is higher than the threshold, the customer will be offered the express service at the regular price, without any extra charge.     

ON PROPERITIES OF A SERIAL SERVICE SYSTEM OF TWO SERVICE COUNTERS WITH FINITE WAITING SPACE

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A Two Priority Queue with Crossover Feedback

This paper considers the delay distributions in a two-class non-preemptive priority queue with crossover feedback. Specifically, there are two priority classes, and the Poisson arrival process for each class can be subdivided into two groups: one group which only requires service at the priority level to which it arrives, and another group which requires subsequent service after it feeds back to the other queue. Our main result is the determination of explicit expressions for the distribution of delay until final service commences for each the four types of customers.     

The Setting and Optimization of Quick Queue

Considering that customer arrival is a peak and post-peak period, we establish a fluid model of queuing behavior. In order to reduce the sum of waiting time of customers, we study the method of the setting and optimization of quick queue in a random service system. Under the premise of the total number of service equipment, we construct two queuing models, with one including only common queues and the other including both common and quick queues and propose the formulas for calculating the sum of the waiting time of the two models. In the two cases of peak and post-peak periods, we analyze the effect of quick queue on service system performance. And we present the method for calculating the number of quick queues that gives the best overall system performance. Taking the quick queue setting and optimization of the supermarket service system as an example, we verify the validity of the proposed method, which indicates the reference value of the method to the management practice.     

Competition and contracting in service industries

In service industries with congestion effects, two very different contractual structures are commonly observed, depending on whether or not firms choose to offer a guaranteed service level. We analyze the impact of these choices on market outcomes in oligopolistic industries. Our results highlight how different contractual agreements change the intensity of price competition in service industries. Broadly speaking, we show that competition is intensified when firms choose to offer service level guarantees.