Determining extreme capability requirements using orthogonal arrays: an empirical study

The basis of defence planning has, in the past few years, shifted from large single conventional wars to that of preparation for concurrent operations in multiple theatres. Planners often assume that future operations would have staggered starts. This assumption makes the sequence in which the operations are executed consequential with respect to the levels of capabilities needed to meet requirements. Often, the most demanding sequence is determined by conducting a complete enumeration of all possible sequencing of the planning scenarios. The most stringent capability requirement so determined is then used for planning. This paper provides results of a simulation study that shows that it is possible to get a requirement specification that is adequate for over 92% of all future possibilities, using considerably fewer sequences based on orthogonal arrays (56 instead of 40 320 sequences in the case of eight planning scenarios). It also shows that, contrary to popular perception, staggering the starts of the operations does not necessarily lead to reduced requirements. Journal of the Operational Research Society (2011) 62, 1574-1584. doi:10.1057/jors.2010.117 Published online 1 September 2010