Service Systems with Outbound Work and Blending

具有出库工作和混合功能的服务系统

• 批准号: 1436518
• 负责人: Ohad Perry
• 金额: $ 29.6万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1436518&HistoricalAwards=false
• 关键词: Service; Systems; Outbound; Work; Blending

The research objective of this award is to develop new models and control mechanisms that faithfully describe contemporary service systems, such as contact centers and healthcare systems, which handle inbound and outbound work simultaneously. Special attention will be given to systems that process the two types of jobs by the same group of agents, a process referred to as "blending," in time-varying or random environments. The most significant difference between the two types of jobs is that inbound work typically arrives exogenously, so that management has no direct control on the arrival rate, whereas the arrival process of outbound work is generated by the system itself, and its arrival rate is therefore mostly controlled. The flexibility in scheduling outbound arrivals can be exploited to improve performance, and in particular, to reduce the variability associated with the arrival process of inbound work. However, outbound work also introduces new types of practical and analytical challenges that do not exist in systems that are dedicated to serving inbound work. For example, modern contact centers employ automatic dialers to generate outbound calls. In a blended service pool, it is then highly possible that all agents are busy by the time a called customer replies, so that the call is dropped. In healthcare settings, a clinic that accepts walk-ins (inbound patients) in addition to scheduled appointments (outbound patients), must take into account no-shows and late arrivals of outbound patients when making staffing and scheduling decisions. Therefore, existing results and insights that are known for systems that handle only inbound work, do not directly extend to systems that process also outbound work. Specific questions that will be addressed are: 1) How to design a system that processes the two types of jobs, e.g., when is it better to use blending, and when is it preferable to handle each type of work by a dedicated service pool. 2) How to best utilize the flexibility in face of time-dependent, or stochastic arrival rates of inbound work. 3) How to staff blended service pools so as to achieve a desired throughput rate of outbound work, subject to given service-level constraints for both inbound and outbound customers. 4) How to route customers and schedule agents in real time. If successful, this research will develop new methods and tools to design and control large service systems with outbound work and blending in non-stationary settings. Since exact analysis is prohibitively hard, novel many-server heavy-traffic limits will be proved and shown to provide effective approximations. A challenging characteristic of the asymptotic analysis is that the generation of outbound work takes place in a fast time scale, therefore requiring refined heavy-traffic analysis. This property, in addition to the non-stationarity and uncertainty regarding inbound arrival rates, presents technical complications that make limiting arguments hard to derive. Successful results will lead to new types of useful asymptotic techniques and insights which can potentially be applied in other settings as well.

该奖项的研究目标是开发新的模型和控制机制，忠实地描述当代服务系统，例如同时处理入站和出站工作的联络中心和医疗保健系统。将特别关注在时变或随机环境中由同一组代理处理两种类型作业的系统，该过程称为“混合”。两类作业最显着的区别在于，入库作业通常是外生到达的，因此管理层无法直接控制到达率，而出库作业的到达过程是由系统本身生成的，因此其到达率大多受到控制。可以利用调度出站到达的灵活性来提高性能，特别是减少与入站工作的到达过程相关的可变性。然而，出站工作也带来了新类型的实践和分析挑战，而这些挑战在专门为入站工作提供服务的系统中并不存在。例如，现代联络中心采用自动拨号器来生成出站呼叫。在混合服务池中，当被叫客户回复时，所有座席很可能都处于忙碌状态，从而导致呼叫中断。在医疗保健环境中，除了预约（出院患者）之外还接受预约（入院患者）的诊所，在制定人员配置和日程安排决策时，必须考虑出院患者的缺席和迟到情况。因此，仅处理入站工作的系统已知的现有结果和见解不会直接扩展到也处理出站工作的系统。将要解决的具体问题是：1）如何设计一个处理两种类型工作的系统，例如，什么时候最好使用混合，什么时候最好由专用服务池处理每种类型的工作。 2) 如何最好地利用灵活性来应对时间相关或随机的入站工作到达率。 3) 如何为混合服务池配备人员，以达到期望的出站工作吞吐率，同时满足入站和出站客户的给定服务水平限制。 4）如何实时路由客户并安排座席。 如果成功，这项研究将开发新的方法和工具来设计和控制具有外出工作和非固定环境混合的大型服务系统。由于精确分析极其困难，因此将证明并证明新颖的多服务器大流量限制可提供有效的近似值。渐近分析的一个具有挑战性的特征是出站工作的生成发生在快速的时间范围内，因此需要精细的大流量分析。除了入境到达率的非平稳性和不确定性之外，这一特性还带来了技术上的复杂性，使得限制论据难以得出。成功的结果将带来新型有用的渐近技术和见解，这些技术和见解也有可能应用于其他环境。