Because Function Point Analysis (FPA) has now been in use for a decade, and in spite of its increasing popularity has met with some recent criticisms, it is time to review how appropriate it still is for today's technologies. A critical review of the FPA approach examines in particular the pioneering and continuing work of Albrecht and more recent work by Symons. Technological dependencies in FPA-type metrics are identified and a general model for deriving a new FPA-type metric for a new software technology is given. A model for the calibration of FPA-type metrics for new technologies in terms of a reference technology is also presented. Such calibration is essential for comparative productivity studies. The role of module estimation in exposing parts of the 'anatomy' of the FPA approach is investigated. The derivation and calibration models are applied to a significant case study in which a new FPA-type metric suited to a particular software development technology is derived, calibrated and compared with other published versions of FPA metrics.