One of the major problems in current technology in the military environment is the identification of failures that occur in airborne electronics while on a mission that cannot be reproduced on the ground-in other words, return tested OK (RTOK). A module that monitors environmental conditions, real time, called the Time Stress Measurement Module (TSMM) is described. TSMM monitors environmental conditions affecting electronics modules and within electronic systems for test, maintenance, and AVIP purposes. The current TSMM provides for monitoring of temperatures, vibration, shock, voltage variations, and transients. The sensor data can be accessed across the PI-bus at any time before, during, or after a mission while the module is installed, allowing an expert system to take extreme environmental conditions and predict failures or correlate that data against failures that have already occurred. The sensor data can be retained after loss of power. >