基于飞行品质数据的飞行员调度模型研究

随着近几年我国航空业的迅猛发展,各大航空公司都在不断扩张自身规模,增加任务量,同时各公司又必须在保障安全的前提下进行飞行生产活动,这就使得飞行员的调度工作更为重要。本文在传统的飞行员调度模型基础上充分考虑安全的因素提出基于飞行品质数据的飞行员调度模型。通过考察调度过程中飞行员前期飞行品质表现情况,对飞行品质数据进行分类,设定搭配规则限制某些飞行品质分类级别较低的飞行员组成机组,实现提高排班安全性的目的。文中提出了根据飞行员工龄和千次率的分类方法,并运用列生成算法求解以周为单位的调度模型,这对于我国航空公司"安全第一,保障生产"的要求有着一定的借鉴意义。     

Airline Safety Improvement Through Experience with Near‐Misses: A Cautionary Tale

In recent years, the U.S. commercial airline industry has achieved unprecedented levels of safety, with the statistical risk associated with U.S. commercial aviation falling to 0.003 fatalities per 100 million passengers. But decades of research on organizational learning show that success often breeds complacency and failure inspires improvement. With accidents as rare events, can the airline industry continue safety advancements? This question is complicated by the complex system in which the industry operates where chance combinations of multiple factors contribute to what are largely probabilistic (rather than deterministic) outcomes. Thus, some apparent successes are realized because of good fortune rather than good processes, and this research intends to bring attention to these events, the near‐misses. The processes that create these near‐misses could pose a threat if multiple contributing factors combine in adverse ways without the intervention of good fortune. Yet, near‐misses (if recognized as such) can, theoretically, offer a mechanism for continuing safety improvements, above and beyond learning gleaned from observable failure. We test whether or not this learning is apparent in the airline industry. Using data from 1990 to 2007, fixed effects Poisson regressions show that airlines learn from accidents (their own and others), and from one category of near‐misses—those where the possible dangers are salient. Unfortunately, airlines do not improve following near‐miss incidents when the focal event has no clear warnings of significant danger. Therefore, while airlines need to and can learn from certain near‐misses, we conclude with recommendations for improving airline learning from all near‐misses.     

Operations research in the management of the airlines

This paper is intended to present an introduction to the use of operations research in the international airline industry, and to demonstrate the scope and significance of the airline OR activities. First, the special reasons for the viability and spread of airline OR are discussed. Then a functional framework for an airline is outlined, to be used in analyzing the problems of an airline and relating the OR work to it. Four major applications are described, corresponding to four major components of the framework. These applications are: schedule development, overbooking control, crew scheduling and engine management, respectively. In each case we describe the problem and its significance, indicate the types of solution techniques which have been developed, and assess the implemented solutions. The paper concludes with comments on the current state-of-the-art and the future of airline OR. A detailed bibliography is given.Both of the authors have been operations research directors in major airlines and more recently have focused their attention upon the industry as academic researchers. This background has provided us with an unusual opportunity to analyze the role of OR in the airlines, and our paper seeks to share with the reader some of the insights we have gained thereby.     

Exploring the Conceptual Foundation of Continuity Management in the Context of Societal Safety

Public and private actors with critical roles for ensuring societal safety need to work proactively to reduce risks and vulnerabilities. Traditionally, risk management activities have often been performed in order to ensure continuous functioning of key societal services. Recently, however, business continuity management (BCM), and its analytical subcomponent business impact assessment (BIA), has been introduced and used more extensively by both the private and public sector in order to increase the robustness and resilience of critical infrastructures and societal functions and services. BCM was originally developed in the business sector but has received a broader use during the last decade. Yet, BCM/BIA has gained limited attention in the scientific literature—especially when it comes to clarifying and developing its conceptual basis. First, this article examines and discusses the conceptual foundation of BCM concepts, including practical challenges of applying the concepts. Based on recent conceptual developments from the field of risk management, a developed conceptualization is suggested. Second, the article discusses challenges that arise when applying BCM in the societal safety area and provides some recommendations aiming to improve the clarity and quality of applications. Third, the article provides suggestions of how to integrate the overlapping approaches of BIA and risk assessment in order to improve efficiency and effectiveness of proactive, analytic processes. We hope that the article can stimulate a critical discussion about the key concepts of BCM, their wider use in societal safety, and their connection to other concepts and activities such as risk assessment.     

Reliability evaluation for airline network design in response to fluctuation in passenger demand

This study develops a reliability evaluation method for airline network design. Reliability evaluation in the airline network design phase is considered herein as a post-design task. A series of models for determining flight frequencies on individual routes, evaluating reliability under normal/abnormal demand fluctuations, and providing a priori adjustment of flight frequencies are presented. A case study demonstrating the feasibility of applying the proposed models is provided. Study results not only suggest a post evaluation and adjustment method for airline network design in response to future uncertain fluctuation in passenger demand, but also provide ways to improve flexibility in airline flight frequency decision-making.     

Approaches to solve the fleet-assignment,aircraft-routing,crew-pairing and crew-rostering problems of a regional carrier

This paper presents the results of a research project funded by a regional carrier operating inter-island services within the Canary Islands (Spain) in addition to services to Morocco and Portugal. It operates between 100 and 150 flights a day using three airline operators. The main scope of the project was to solve fleet-assignment, aircraft-routing, crew-pairing and crew-rostering problems on real-world data. The special characteristics of the carrier, flying between 7 am and 11 pm every day, have motivated us to design models and algorithms that are different than the ones addressed in the literature, typically built for large airline companies. This paper shows a solution approach for an integrated fleet-assignment, aircraft-routing and crew-pairing problem covering the flights of a single day. This is a new combinatorial problem that can be considered as a 2-depot vehicle routing problem with driver changes, where the vehicles represent aircrafts and the drivers represent crews. Adapting approaches from the vehicle routing literature, this paper describes a heuristic algorithm based on an integer programming model. In a similar way, this paper also addresses the rostering problem. This problem can be decomposed in smaller problems taking into account operators, bases and crew groups. These problems admit a compact formulation through mixed integer linear programming models which can be tracked by modern general-purpose solvers. This paper illustrates the success of our solution approaches on real-world instances. The airline carrier is currently using these approaches.     

Safety Management and Public Spaces: Restoring Balance

Since 2000, the reputation of health and safety in the United Kingdom has been tarnished, so much so that it has become the subject of both a media circus and a government inquiry. This not only threatens the worthy goals of health and safety, but also impacts upon the associated tool of risk assessment itself such that "risk assessment" is increasingly seen by the public at large as a term inviting ridicule, even abuse. The main thrust of the government's examination of health and safety has been its concern that safety requirements were placing a disproportionate burden on business. However, there is another source of discontent, which is public chagrin over the impact of injury control measures upon life beyond the conventional workplace, in particular upon the public spaces that people frequent in their leisure time and on the activities they engage in there. This article provides a perspective on this second dimension of the crisis in confidence. It describes how many U.K. agencies with responsibilities for a wide portfolio of public amenities ranging from the provision of play spaces for the young to the management of publicly accessible countryside, the maintenance of urban and rural trees, the stewardship of sites of cultural heritage, and the pursuit of outdoor educational activities have responded to some conflicts posed to their services by the new safety culture. It concludes with a discussion of implications for the management of public space and for risk assessment itself.     

航空公司收入管理价格与舱位控制的统一分析

收入管理对于改善民航企业的经济效益、增强民航企业的竞争能力具有重大意义. 文章 运用随机过程理论和最大凹向包络原理,探讨航空公司客运收入管理研究中动态价格与舱位 控制的统一分析模型,即在任意订票时刻,决定航班的哪些舱位该开放,以什么价格开放,从而 实现单个航班的收入最大化. 文章指出,航空公司可通过三阶段方法来获取最优的动态价格与 舱位控制策略,即确定最优价格集、开放舱位数及最优价格. 最后给出了实例分析.     

Corporate planning in domestic airlines— An Indian case study

In this article the author considers the problems of planning in the airline industry, drawing specifically on experience in the domestic Indian airline. The article seeks to examine some of the strategic issues relevant to domestic airlines which, while related here to the Indian environment, may be seen to be pertinent in most developing countries.     

Significant Factors of Aviation Insurance and Risk Management Strategy: An Empirical Study of Taiwanese Airline Carriers

Aviation insurance premiums have become a heavy burden for the airline industry since September 11, 2001. Although the industry must constantly balance its operations between profitability and safety, the reality is that airlines are in the business of making money. Therefore, their ability to reduce cost and manage risk is a key factor for success. Unlike past research, which used subjective judgment methods, this study applied quantitative historical data (1999–2000) and gray relation analysis to identify the primary factors influencing ratemaking for aviation insurance premiums. An empirical study of six airlines in Taiwan was conducted to determine these factors and to analyze the management strategies used to deal with them. Results showed that the loss experience and performance of individual airlines were the key elements associated with aviation insurance premiums paid by each airline. By identifying and understanding the primary factors influencing ratemaking for aviation insurance, airlines will better understand their relative operational strengths and weaknesses, and further help top management identify areas for further improvement. Knowledge of these factors combined with effective risk management strategies, may result in lower premiums and operating costs for airline companies.     

Measuring the Benefit of Offering Auxiliary Services: Do Bag‐Checkers Differ in Their Sensitivities to Airline Itinerary Attributes?

When firms evaluate their service system design choices, there is typically more uncertainty surrounding the value that a particular auxiliary service provides than there is on the cost of providing that service. To help inform this decision, we propose an approach where we compare the relative value of the segment of passengers who use an auxiliary service to the relative value of the segment that does not use it. We demonstrate this approach for a typical auxiliary service common to the airline industry. In 2008, most US airlines implemented checked baggage fee policies to decrease their costs by reducing the number of customer service agents needed in the check‐in and baggage handling processes. The success of this change has led to a current debate at many of these airlines on whether to make further staffing cuts in these areas, essentially making it even less attractive for passengers to check their baggage. Our proposed methodology helps answer whether passengers who continue to check bags in today's baggage‐fee era are more or less valuable than passengers who do not check bags. We explore this question empirically by examining, through a stated preference survey, if a history of checking or not checking bags can be used to segment passengers based on how their itinerary choices are influenced by common airline service attributes (on‐time performance, itinerary time, number of connections, airfare, and schedule delay). Contrary to the opinions of some top airline executives, we find that the passengers who continue to check bags at airlines that charge baggage fees are generally less sensitive to differences in three of these important service attributes and are less likely to switch airlines when a competing airline improves its offerings along these dimensions. Thus, airlines that charge for checked bags should consider improving the customer experience for their bag‐checking passengers, as they represent a potentially more valuable segment class to the airline.     

航空公司与旅行社的协作机制研究

旅行社是航空公司机票销售网络中非常重要的一环。作为一种特殊的机票代理,为了应对旅游旺季的旅客需求,旅行社往往会提前较长时间从航空公司预订机票。对于航空公司来说,提前预订机票给旅行社是降低销售风险的一个重要途径。在进行机票预订交易时,双方都必须进行慎重的决策;旅行社决策最优的预订数量;航空公司决策最优的供给量。本文正是在对双方各自最优决策探讨的基础上,对双方的协作机制进行了研究。在模型中,我们考虑了双方的缺票损失、航空公司的超额预订等因素。双方协作的目标是在实现整体收益最大化的基础上,同时实现航空公司和旅行社各自的收益更大化。本文提出了一种中间价格调整的协作机制,并说明了这种机制的可行性和收敛性。     

基于贝叶斯网络的航空安全中不安全信息分析

针对航空安全中收集到的不安全信息,本文将安全检查发现的问题进行了分类,建立了民航安全检查的故障树模型,同时利用故障树模型进行了最小割集、结构重要度的定性分析。然后利用贝叶斯网络的学习能力结合故障树模型最终构建了民航安全检查贝叶斯网络模型,基于某航空公司安全检查发现问题的数据并利用贝叶斯网络的双向推理计算得到各影响因素对不安全事件的影响程度和不安全事件发生时各影响因素的重要程度。基于民航安全检查贝叶斯网络模型分析,本文得出个体原因、设施不完善、信息沟通因素最易导致工作流程管理中发现问题;管理流程、知识技能不足最易导致人员管理中发现问题;个体原因、培训、设备故障最易导致设备管理中发现问题。     

Using Related Samples in Assessing Conformance to Safety Goals: A Nuclear Reactor Safety Application

Quantifying safety goals is a key to the regulation of activities which are beneficial on the whole but entail some risks in being performed. Determining compliance with safety goals involves dealing with uncertainties. A recent article by Bier^(I) describes some of the difficulties encountered using measures with uncertainty to determine compliance with safety goals for nuclear reactors. This paper uses a hierarchical Bayes approach to address two practical modeling problems in determining safety goal compliance under uncertainty: (1) allowing some modeling assumptions to be relaxed, and (2) allowing data from previous related samples to be included in the analysis. The two issues effect each other to the extent that relaxing some assumptions allows the use of a broader range of data. The usefulness of these changes and their impact on assessing safety compliance for nuclear reactors is shown.     

Psychophysiological coherence training to moderate air traffic controllers’ fatigue on rotating roster

The nature of the current rotating roster, providing 24-h air traffic services over five irregular shifts, leads to accumulated fatigue which impairs air traffic controllers’ cognitive function and task performance. It is imperative to develop an effective fatigue risk management system to improve aviation safety based upon scientific approaches. Two empirical studies were conducted to address this issue. Study 1 investigated the mixed effect of circadian rhythm disorders and resource depletion on controllers’ accumulated fatigue. Then, study 2 proposed a potential biofeedback solution of quick coherence technique which can mitigate air traffic controllers’ (ATCOs’) fatigue while on controller working position and improve ATCOs’ mental/physical health. The current two-studies demonstrated a scientific approach to fatigue analysis and fatigue risk mitigation in the air traffic services domain. This research offers insights into the fluctuation of ATCO fatigue levels and the influence of a numbers of factors related to circadian rhythm and resource depletion impact on fatigue levels on study 1; and provides psychophysiological coherence training to increase ATCOs’ fatigue resilience to mitigate negative impacts of fatigue on study 2. Based on these two studies, the authors recommended that an extra short break for air traffic controllers to permit practicing the quick coherence breathing technique for 5 min at the sixth working hour could substantially recharge cognitive resources and increase fatigue resilience. Application: Present studies highlight an effective fatigue intervention based on objective biofeedback to moderate controllers’ accumulated fatigue as a result of rotating shift work. Accordingly, air navigation services providers and regulators can develop fatigue risk management systems based on scientific approaches to improve aviation safety and air traffic controller's wellbeing.     

Evaluation of safety stock methods in multilevel material requirements planning (MRP) systems

This paper evaluates alternative methods of establishing the safety stock level taking into consideration of historical measures of forecasting accuracy and the needs for master production scheduling and material requirement planning under a rolling time horizon. A computer model is used to simulate the forecasting, master production scheduling and material planning activities in a company that produces to stock and the production activities are managed by multilevel MRP systems. The simulation output is analysed to evaluate the impact of safety stock methods on MRP system performance. The result of the study shows that using safety stock can help to reduce total cost, schedule instability and improve service level in the MRP systems. Guidelines are developed to help managers select methods to determine safety stock in MRP system operations.     

Is It Safer to Fly or Drive?

In attempts to soothe the nascent fear of the scheduled airline traveler, passengers waiting takeoff are sometimes reminded of the cliche that they may have already completed the most dangerous part of their trip — the drive to the airport. The objective of this paper is to communicate under what conditions air travel is indeed safer than highway travel and vice versa. The conventional wisdom among risk communicators that air travel is so much safer than car travel arises from the most widely quoted death rates per billion miles for each — 0.6 for air compared to 24 for road. There are three reasons why such an unqualified comparison of aggregated fatality rates is inappropriate. First, the airline rate is passenger fatalities per passenger mile, whereas the road rate is all fatalities (any occupants, pedestrians, etc.) per vehicle mile. Second, road travel that competes with air travel is on the rural interstate system, not on average roads. Third, driver and vehicle characteristics, and driver behavior, lead to car-driver risks that vary over a wide range. Expressions derived to compare risk for drivers with given characteristics to those on airline trips of given distance showed that 40-year-old, belted, alcohol-free drivers of cars 700 pounds heavier than average are slightly less likely to be killed in 600 miles of rural interstate driving than in airline trips of the same length. Compared to this driver, 18-year-old, unbelted, intoxicated, male drivers of cars 700 pounds lighter than average have a risk over 1000 times greater. Furthermore, it is shown that the cliche above is untrue for a group of drivers having the age distribution of airline passengers.     

航空公司战略联盟的经济动因分析

本文从经济学角度讨论航空公司战略联盟的动因,认为航空公司联盟旨在节约生产成本和交易成本。本文分析了航空公司战略联盟的网络经济性,基于交易成本经济学分析了航空公司联盟相对于市场而言对交易成本的节约。本文提出修正的威廉姆森启发式模型,并将其应用于分析和比较在国际航空运输市场中完整航空客运产品的实现方式。     

航空公司交叉持股对产能共享策略的影响研究

产能共享与交叉持股是航空公司常用的运作与财务策略,两种方式都能在一定条件下起到缓和竞争的作用。本文考虑两家航空公司的两种交叉持股模式,构建了包含顾客忠诚度的价格竞争模型,依据产能是否对称以及是否实施产能共享策略形成八种不同的情形,求解并分析了不同情形下的最优价格决策及对应期望利润。通过对比不同情形下的利润,本文发现,在单向持股模式下,当产能对称时,两家企业始终愿意采用产能共享策略,而当产能不对称时,如果存在产能共享,产能较小的企业将更愿意降低产品价格,导致市场竞争加剧,从而损害产能较大企业的盈利能力。因此,只有当持股比例相对较小时企业才愿意实施共享产能策略。在交叉持股模式下,当产能对称时,企业在交叉持股比例适中时才愿意实施产能共享策略。而当产能不对称时,企业始终不愿意采用产能共享策略。这也表明产能共享和交叉持股策略之间存在一定的相互替代作用,企业应根据不同市场状态协调使用两种策略。     

Improving Revenue Management Decision Making for Airlines by Evaluating Analyst‐Adjusted Passenger Demand Forecasts*

To maximize revenue, airline revenue management analysts (RMAs) attempt to protect the right number of seats for late‐booking, high‐revenue‐generating passengers from low‐valued leisure passengers. Simulation results in the past showed that a major airline can generate approximately $500 million per year through efficient RM operations. Accurate passenger demand forecasts are required, because reduced forecast error significantly improves revenue. RMAs often adjust the system forecasts to improve revenue opportunity. Analysis of system forecast performance and analyst adjustment is complex, because one must account for all unseen demands throughout the life of a flight. This article proposes a method to account for unseen demand and evaluate forecast performance (adjusted or unadjusted) through a forecast monitoring system. Initial results from one major airline's origin‐destination market data justify the value of RMA forecasting adjustments.