Mandated defence offsets: can they ever deliver?

Defence offsets are elements of defence procurement deals additional to the primary content. Offsets are usually expected to yield technological or industrial benefits to the purchasing country (e.g. countertrade, technology transfers, or additional jobs) and military buyers often require suppliers to make offsets available “cost-free.” The authors argued previously that such strategies achieve little of value to buyers that lack market power and are unnecessary otherwise, since purchasers with the market power to extract more value for money from foreign suppliers can do so anyway. This article also focuses on the supply side of offset deals. The USA is the world's largest defence offsets supplier but the US government opposes offsets demands as economically inefficient and trade distorting. Even if offsets are inefficient and trade distorting, they may still benefit a materiel-exporting country such as the USA as they may induce exports and create associated benefits for the offsets provider.     

Book reviews

The Balkanization of the West: The Confluence of Postmodernism and Postcommunism By Stjepan G. Mestrovic, Routledge, London (1994). ISBN: 0-414-08755-4, Price £40.00 hardback, £13.99 paperback.

A Naval History of World War I By Professor Paul G. Halpern, UCL Press, 1994. pp. 624 ISBN 1-85728-295-7. Price £25.00

Arms Watch - SIPRI Report on the First Year of the UN Register of Conventional Arms By Edward J. Laurance, Siemon T. Wezeman and Herbert Wulf, Oxford University Press for SIPRI (1993) ISBN 019-829-1795, Price £25.00 hardback, £16.50 paperback.

A League of Airmen By J. A. Winnefeld, (Ed.), RAND, Santa Monica, ISBN 08330-1503-6, Price $30.00 (Hardcover) $15.00 (Softcover)     

A stochastic constrained optimal replacement model

In this paper a stochastically constrained replacement model is formulated. This model determines a sequence of replacement dates such that the total “current account” cost of all future costs and capital expenditures over an infinite time horizon for the n initial incumbent machines is minimized subject to the constraints that an expected number of machines are in a chosen utility class at any point in time. We then indicate one possible solution method for the model.     

Attack and defense of ICBMs deceptively based in a number of identical areas

On-site verification of ICBMs in the context of an arms control agreement might involve a situation where an inspector would choose one or more of a number of identical areas to inspect and would have confidence that the other areas had the same characteristics. This article considers optimal attack and defense of missiles deceptively based in a number of identical areas. The attacker may allocate warheads across areas as he desires and uniformly within areas. The defender may allocate interceptors across areas as he desires and either uniformly or preferentially within areas. The effect of restricting the defender to uniform allocation across areas is explored for various assumptions. Robustness of surviving missiles with respect to the number of attacking warheads is studied. Results are presented for a wide range of cases.     

Applying Lanchester's linear law to model the Ardennes campaign

In modern warfare, many believe the decisive factor in winning a battle is seizing the right moment to shift from defense to attack, or vice versa. This paper attempts to bring that perspective to Lanchester's differential equations of warfare, and continues the application of Lanchester's linear law to the analysis of the World War II battle of Ardennes, as reported in earlier issues of Naval Research Logistics by Bracken and by Fricker. A new variable, shift time, accounting for the timing of the shift between defense and attack is explicitly included in our version of the model, and it helps obtain improved goodness of fit to historical data. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48:653–661, 2001     

Real-time task scheduling with overheads considered

n periodic tasks are to be processed by a single machine, where each task i has a maximum request rate or periodicity F_i, a processing time E_i, a deadline D_i, relative to each request of task i, a task-request interrupt overhead I_i, and a task-independent scheduling overhead S. Two scheduling strategies are considered for sequencing the execution of an arbitrary arrangement of task requests in time: the preemptive and the nonpreemptive earliest-deadline algorithms. Necessary and sufficient conditions are derived for establishing whether a given set of tasks can be scheduled by each scheduling strategy. The conditions are given in the form of limited simulations of a small number of well-defined task-request arrangements. If all simulations succeed, the schedule is feasible for the given set of tasks. If any simulation fails, the schedule is infeasible. While interrupt handling and scheduling overheads can be handled by such simulations, context switching overhead resulting from preemption cannot. A counterexample illustrates how the simulations fail to uncover unschedulable task sets when context switching overhead is considered.