The TAKATA Intelligent Total Restraint System, or ITRS, is a controllable vehicle occupant restraint system optimized so as to cost effectively minimize the risk of injury to occupants from crashes. A model based technique is described for optimizing the perfomance of the ITRS. The ITRS senses occupant Weight, occupant position, crash Verity, and seat belt usage; and in response to these sensed measurements, controls the individual firing times of a two-stage inflator. A general form of the ITRS also controls ínflator module vent area, seat belt force limit, and a seat belt pretensioning. The first stage inilator is experimentally sized so as to not injure the worst case out-of-position occupant, While the combined gas generant loading 0f both stages is sufficient to satisfy FMVSS-208 requirements. Given the system architecture and associated fixed parameters, occupant injury and injury assessment value (IAV) measures are each modeled as a function ofthe input and control variables using data gathered from an occupant simulation experiment comprising combinations of occu» pant size, occupant position, crash severity, and air bag inrate. Optimal controls are found by minimizing the IAV model with respect to the system controls subject to constraints that individual injury measures be less than corresponding threshold values. Inflation rate is dependent upon the system state, defined by occupant position, occu~ pant Weight, seat belt usage, and crash severity, Where crash severity is defined as the injury producing potential of the crash. The air bag firing threshold is found as the maximum crash severity which satisfies the constraints that occupant Contact velocity is less than 19 KPH and shoulder belt load is less than 3 KN. Second stage inflator time delay is found which minimizes the lAV subject to the constraint that individual injury measures do not exceed acceptable threshold limits. If an air bag is warranted for a given crash the first stage inflator is fired as soon as possible to allow for the longest possible inflation interval or softest possible inflation as controlled by the second stage inflator time delay. Results from a driver-side firing threshold study demonstrate the potential for benefit from an ITRS.