Embodiments of the present invention provide a semiconductor sensor reliability system and method. Specifically, the present invention provides in-situ positioning of a reliability sensor (hereinafter sensors) within each functional block, as well as at critical locations, of a semiconductor system. The quantity and location of the sensors are optimized to have maximum sensitivity to known process variations. In general, the sensor models a behavior (e.g., aging process) of the location (e.g., functional block) in which it is positioned and comprises a plurality of stages connected as a network and a self-digitizer. Each sensor has a mode selection input for selecting a mode thereof and an operational trigger input for enabling the sensor to model the behavior. The model selection input and operation trigger enable the sensor to have an operational mode in which the plurality of sensors are subject to an aging process, as well as a measurement mode in which an age of the plurality of sensors is outputted.