Rollover Protective Structures (ROPSs) are used in off-highway vehicles to protect operator in case of accidents involving overturning of vehicle. The role of a ROPS is to absorb the energy of Rollover without violating the protected operator zone. The performance of a ROPS is determined by its ability to absorb energy under prescribed loading conditions. The performance depends upon design parameters, such as tube thicknesses, material grades, ROPS tube cross-sections, etc., that define the structure.In this paper, we describe a method that uses Design of Experiments (DOE) to determine the correlation between the performance of a ROPS for a small tractor and its critical design parameters. The correlation results are discussed for two types of loading conditions, namely “front push loading” and “side push loading”. The correlation obtained is further used to identify the optimal design parameters for maximum energy absorption under constraints on allowable deflections.