Some metrics from a formal development

A frequent complaint about the use of formal methods is that projects using them do not capture quantitative data that can help to evaluate the impact of the methods. We describe the measures used to analyze the quality of a formal development. The project we describe is a large industrial development undertaken by Praxis between 1989 and 1992. It was to develop CDIS, a system for display and manipulation of information used by air traffic controllers in the new terminal control room at the London Area and Terminal Control Centre. (4 pages)