A process for designing dump bodies which more accurately takes into account field loading/haulage conditions is provided. The process includes gathering data from actual field environments including material density, front, rear and side angles of material repose and corner void information. From this data, a three dimensional model of the load is generated. This three dimensional load model is then used to design the truck body in an iterative process until the volume of the truck body and the distribution of weight of the three dimensional load model on the truck chassis is substantially the same as the desired volume and the distribution of weight on the truck chassis.