Revenue management with aircraft reassignment flexibility

A well‐studied problem in airline revenue management is the optimal allocation of seat inventory among different fare‐classes, given a capacity for the flight and a demand distribution for each class. In practice, capacity on a flight does not have to be fixed; airlines can exercise some flexibility on the supply side by swapping aircraft of different capacities between flights as partial booking information is gathered. This provides the airline with the capability to more effectively match their supply and demand. In this paper, we study the seat inventory control problem considering the aircraft swapping option. For theoretical and practical purposes, we restrict our attention to the class of booking limit policies. Our analytical results demonstrate that booking limits considering the swapping option can be considerably different from those under fixed capacity. We also show that principles on the relationship between the optimal booking limits and demand characteristics (size and risk) developed for the fixed‐capacity problem no longer hold when swapping is an option. We develop new principles and insights on how demand characteristics affect the optimal booking limits under the swapping possibility. We also develop an easy to implement heuristic for determining the booking limits under the swapping option and show, through a numerical study, that the heuristic generates revenues close to those under the optimal booking limits. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

Women and the military

Debates about the relationship between women and the military have become common within Western societies. These debates primarily centre on the issue of the place, fitness and desirability of a female presence within institutions designed for national war making. There are those who claim that equality betwen the sexes demands the full integration of women into national militaries, including in combat roles, others however argue that women are ill‐equipped for the traditional tasks required of ‘warriors’. This article argues that these debates are increasingly irrelevant. Future wars are increasingly less likely to be fought only by clearly defined national combat forces and more likely to be ‘virtual’ wars involving the deployment of Western technologies against militarily inferior opponents. This too is an age in which Western states will be engaged not just in virtual wars but in ‘humanitarian intervention’, peacekeeping, enforcement and postwar reconstruction. This allows, even encourages, a rethinking of traditional notions and debates over the place of women within the military sphere.     

Supplier certification and quality investment in supply chains

Global sourcing has made quality management a more challenging task, and supplier certification has emerged as a solution to overcome suppliers' informational advantage about their product quality. This article analyzes the impact of certification standards on the supplier's investment in quality, when a buyer outsources the production process. Based on our results, deterministic certification may lead to under‐investment in quality improvement technology for efficient suppliers, thereby leading to potential supply chain inefficiency. The introduction of noisy certification may alleviate this under‐investment problem, when the cost of information asymmetry is high. While allowing noisy certification always empowers the buyer to offer a menu to screen among heterogeneous suppliers, the buyer may optimally choose only a limited number of certification standards. Our analysis provides a clear‐cut prediction of the types of certifiers the buyer should use for heterogeneous suppliers, and we identify the conditions under which the supplier benefits from noisy certification. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Bounded flexibility in days‐on and days‐off scheduling

This article presents a flexible days‐on and days‐off scheduling problem and develops an exact branch and price (B&P) algorithm to find solutions. The main objective is to minimize the size of the total workforce required to cover time‐varying demand over a planning horizon that may extend up to 12 weeks. A new aspect of the problem is the general restriction that the number of consecutive days on and the number of consecutive days off must each fall within a predefined range. Moreover, the total assignment of working days in the planning horizon cannot exceed some maximum value. In the B&P framework, the master problem is stated as a set covering‐type problem whose columns are generated iteratively by solving one of three different subproblems. The first is an implicit model, the second is a resource constrained shortest path problem, and the third is a dynamic program. Computational experiments using both real‐word and randomly generated data show that workforce reductions up to 66% are possible with highly flexible days‐on and days‐off patterns. When evaluating the performance of the three subproblems, it was found that each yielded equivalent solutions but the dynamic program proved to be significantly more efficient. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 678–701, 2013     

Basra's not Belfast: the British Army, ‘Small Wars’ and Iraq

This article examines British Army operations in Iraq. It focuses on the causes of the army's apparent failure to live up to its reputation for the conduct of small wars. The paper discusses the British experience of small wars in the context of Iraq, the influence of doctrine and strategy, and the political and moral factors that shaped the army's performance. The paper's conclusions suggest that the Iraq War may cause a significant reappraisal, not just of military doctrine and strategy, but also of Britain's role in future small wars.     

Book reviews

Book Review: The Future of the Defence Firm: New Challenges, New Directions. Edited by Andrew Latham and Nicholas Hooper NATO ASI Series, Kluwer Academic Publishers ISBN 0–7923–3268–7

James E. Payne and Anandi P. Sahu (eds.) Defense Spending &; Economic Growth, Boulder, CO: Westview Press, 1993.     

Missile systems: “Flexible modularity” and incremental technological change in military production∗

It is often stated that technological change in the military field is characterised by the introduction of radical innovations rather than by incremental processes of technological change. This article illustrates the diversity of military innovation by arguing that technological change in missiles systems is dominated by incremental change. While some large weapons platforms display the design rigidities normally associated with complex systems, missiles are characterised by “flexible modularity”. Flexible modularity facilitates the continuous introduction of upgrades, and makes missile systems amenable to gradual technological change. Besides, it has significant implications for the future role of missile systems, and poses special problems for missile disarmament and technology control initiatives.