The method of function point analysis was developed by A. J. Albrecht (1979) to help measure the size of a computerized business information system. Such sizes are needed as a component of the measurement of productivity in system development and maintenance activities, and as a component of estimating the effort needed for such activities. Close examination of the method shows certain weaknesses, and the author proposes a partial alternative. A description is given of the principles of this Mark II approach. The results are presented of some measurements of actual systems to calibrate the Mark II approach, and conclusions are drawn on the validity and applicability of function point analysis generally.< >