The potential of determining the change of injury severity in the accident event taking passive as well as active measures into account at the vehicle (integral systems) are at present limited to pedestrian protective systems. Therefore, an extension of the existing methods for the application with common integral systems (front protection, side protection, etc.) is suggested. Nowadays the effectiveness of passive safety systems is determined in crash tests with very high accident severities. However, approximately 90% of real-world accidents have a lower accident severity as the required crash tests. Thus, this paper will present a method calculating the effectiveness of such an integral system based on real-world accident data. For these reasons, this paper is presenting a method for a more valid prediction of injury severity.The German In-Depth Database GIDAS allows clustering the accident event in relevant car-to-car scenarios. The vehicle dynamics of all scenarios from the database will be simulated in PC-Crash, an accident-reconstruction software. Since the brake assist is obligatory from 2012 on, the system and its effect on each single accident scenario will be modeled. The effect of the restraint system will be calculated with Finite Element Simulation PAM-Crash. The outcome of the occupant simulation, the FMVSS injury criteria (e.g., HIC₃₆), will be converted into the risk factor to suffer an AIS3+ injury for each body region. Finally, the sum of all the injury risks weighted with the relevance of each scenario determines the expected value of MAIS3+ injured persons. Consequently, the percentage of protected MAIS3+ occupants can be calculated and the real-world benefit of an integral safety system can be evaluated.The method described above covers all requirements for calculating the effectiveness of an integral safety system. Therefore, systems influencing vehicle dynamics will be modeled. The effect of these systems on impact situation will be calculated and implemented in the occupant simulation. In combination, by the use of this method the effectiveness of an integral safety system is determined.