During the conceptual phases of a project the operational planning groups in government and industry carry out cost effectiveness analyses, using the techniques described by Mr. Kerr, to chose between various feasible solutions to the problem. Suppose we are dealing; with an anti-aircraft problem (cf. Fig. 1).

There might be two alternatives in the reckoning: solution A, based on guided weapons, and solution B, based on radar controlled guns; or alternatively, two guided weapons solutions; one based on command-to-line-of-sight, and one on semi-active homing.