ABSTRACT
The problem is to find a reliable way of appraising complex projects and of comparing alternative projects. The difficulty with management problems is that the symptoms of each disease vary in different circumstances, which makes diagnosis rather difficult. Many managers have had the experience of receiving a torrent of complaints about the canteen and, in spite of effecting great improvements at enormous expense, the complaints just go on and on. In such circumstances the chances are that these complaints are symptoms of a discontent that can only be tackled at its roots—there is a technique to do this, but there is no technique for stopping complaints about canteens! The management techniques can be, and are, used for attack as well as for defence: that is to say, they can not only be used to solve problems—a defensive use—but also to search out and exploit opportunities—an offensive use.
