Stochastic call center staffing with uncertain arrival,service and abandonment rates: A Bayesian perspective

In this article, we introduce staffing strategies for the Erlang‐A queuing system in call center operations with uncertain arrival, service, and abandonment rates. In doing so, we model the system rates using gamma distributions that create randomness in operating characteristics used in the optimization formulation. We divide the day into discrete time intervals where a simulation based stochastic programming method is used to determine staffing levels. More specifically, we develop a model to select the optimal number of agents required for a given time interval by minimizing an expected cost function, which consists of agent and abandonment (opportunity) costs, while considering the service quality requirements such as the delay probability. The objective function as well as the constraints in our formulation are random variables. The novelty of our approach is to introduce a solution method for the staffing of an operation where all three system rates (arrival, service, and abandonment) are random variables. We illustrate the use of the proposed model using both real and simulated call center data. In addition, we provide solution comparisons across different formulations, consider a dynamic extension, and discuss sensitivity implications of changing constraint upper bounds as well as prior hyper‐parameters. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 460–478, 2016     

警务实战行动中的“危险评估”刍议

警务实战行动情况错综复杂,充满突变性,极具危险性,警察执法危险系数呈上升趋势。如何对警务实战行动中所面临的危险进行及时、准确、全面、客观的评估,从而提高其成功率和效率,是每个参战警察必须具备的执法能力。     

基于组合熵权的联合作战目标选择模型研究

针对作战中目标选择与排序问题,分析确定了8种在联合作战条件下影响目标选择关键因素。在此基础上应用多属性决策理论,以组合熵权系数确定指标权重,建立了目标选择模型。模型简洁易于实现,并且在决策中有效减少了主观随意性。最后通过仿真实例说明了模型的有效性和可操作性。     

Integrating the Services and Harnessing the Military Area Commands

ABSTRACT

The Chinese People’s Liberation Army (PLA) is halfway through a multi-decade modernization process. It has begun a major restructuring effort as it shifts its focus from a traditional continental defensive posture to a more maritime-oriented emphasis. In order to create more balanced joint force, it has adjusted the structure of its highest command organization, the Central Military Commission; abolished the former four General Departments and seven Military Regions; created five new joint Theater Commands and service-level commands for the Army and Rocket Force; and is reducing the size of its active duty force by 300,000 personnel. While seeking to overcome numerous internal obstacles, the PLA continues to develop and improve its capabilities to conduct integrated joint operations to deter a variety of threats to China’s sovereignty and territory and, if deterrence fails, to win informationized local war.     

美国网络空间作战能力建设

网络空间越来越被世界各国公认为是继陆地、海洋、空中和太空之后的第五个作战域,为获得和保持像其它作战域那样世界领先的军事优势,美国正在大力进行网络空间作战能力建设。提出了美国网络空间作战能力建设框架,从战略规划、作战力量、作战理论、作战训练、武器装备、战场基础环境、人才培养和作战联盟八个方面全面总结了美国近年来在网络空间作战能力建设方面的主要做法。     

Mediation,Peacekeeping And Civil War Peace Agreements

The post-civil war agreement phase is vulnerable to credible commitment problems, a lack of government capacity to implement, and/or mutual vulnerability to retribution from violating the agreement. This study’s main contribution is to demonstrate the combined utility of mediation and UN peacekeeping. Mediation builds trust and confidence and works with the parties to design an efficacious agreement conducive to, among other features, tamping down post-agreement violence. Peacekeeping stems violence and facilitates the implementation of the agreement. Agreements that are mediated and followed by UN peacekeeping are expected to be more robust in terms of staving off violence. We report the effects of the mediation–peacekeeping interaction using a method correcting for a common misinterpretation of interaction terms. We test logit and hazard models using a sample of full and partial civil war peace agreements signed between 1975 and 2011. Controlling for agreement design, democracy, and income per capita, the results indicate mediation and its interaction with peacekeeping reduce the probability of renewed/continuing violence and have a positive impact on agreement duration. We also report brief case study evidence from the 1990s peace process in Guatemala.     

Spaghetti: systems thinking and the US Army

In the mid-2000s, the United States Army was embroiled in counterinsurgency missions in Iraq and Afghanistan that required deeper understanding of local social systems. The Army turned to systems thinking and design thinking to model and understand the world, define problems, and develop approaches to strategic and operational challenges. However, the Army’s approach as expressed in publications and doctrine encourages the development of complicated, unsupported, and unfalsifiable hypotheses. The risk is that the Army will act on incorrect assumptions and develop plans that are fragile.     

Precision cyber weapon systems: An important component of a responsible national security strategy?

Given the advances made in conventional weapon capabilities, precision should by now be the accepted and expected norm in cyberspace as well. In this article I argue that developing precision cyber weapon systems, to be used during a lawful conflict, can be an important part of a responsible national security strategy to reduce the amount of violence and physical destruction in conflicts. I first describe a precision cyber weapon system in a military context. I then present three compelling rationales for the development of precision cyber weapon systems based on ethical, operational, and financial considerations. To support the position, I address several arguments that have been levied against their development. Thereafter I present several recommendations for a way ahead.     

Spatial pricing and product allocation in online retailing

Spatial pricing means a retailer price discriminates its customers based on their geographic locations. In this article, we study how an online retailer should jointly allocate multiple products and facilitate spatial price discrimination to maximize profits. When deciding between a centralized product allocation ((i.e., different products are allocated to the same fulfillment center) and decentralized product allocation (ie, different products are allocated to different fulfillment centers), the retailer faces the tradeoff between shipment pooling (ie, shipping multiple products in one package), and demand localization (ie, stocking products to satisfy local demand) based on its understanding of customers' product valuations. In our basic model, we consider two widely used spatial pricing policies: free on board (FOB) pricing that charges each customer the exact amount of shipping cost, and uniform delivered (UD) pricing that provides free shipping. We propose a stylized model and find that centralized product allocation is preferred when demand localization effect is relatively low or shipment pooling benefit is relatively high under both spatial pricing policies. Moreover, centralized product allocation is more preferred under the FOB pricing which encourages the purchase of virtual bundles of multiple products. Furthermore, we respectively extend the UD and FOB pricing policies to flat rate shipping (ie, the firm charges a constant shipping fee for each purchase), and linear rate shipping (ie, the firm sets the shipping fee as a fixed proportion of firm's actual fulfillment costs). While similar observations from the basic model still hold, we find the firm can improve its profit by sharing the fulfillment cost with its customers via the flat rate or linear rate shipping fee structure.     

‘A Brave New World for Chinese Joint Operations’

A key organizational challenge for all modern militaries is instituting an effective command-and-control (C2) structure for joint operations. China has been a relative latecomer to joint operations, with a persistent weakness in joint C2. Reforms launched in early 2016 sought to overcome this challenge by establishing a permanent two-level joint C2 structure. Although not a ‘tipping point’ that will lead ineluctably to stronger operational effectiveness, this reform is nonetheless an important milestone in an evolutionary process towards better PLA joint operations. The result could be added operational challenges for several of China’s neighbors and the United States.