Most guided weapon projects are inherently very difficult to bring to a successful conclusion, and the management methods necessary to achieve the required performance and time-scale, and at the same time to maintain control of costs, have had to be developed and are still developing; the procedures in use are being continually improved and refined. The essential problem in the overall control of a programme is in matching the technical achievement at any time against the corresponding expenditure, hence the involvement of an R & D establishment. There is room for many views on how this objective might best be achieved; those expressed in this paper are the author's and do not necessarily reflect official Government policy.