This paper includes an overview of a collaborative research project of Improved Side Impact Protection (ISIP) that commenced in 1997. The research program was sponsored by the Australian Research Council and involved a partnership of industry, government and research agencies, both in Australia and overseas. The overall aim was to develop a new approach to optimising vehicle design using Harm as the main outcome criteria. The program involved a number of research activities including mass data analysis, in-depth real-world crash investigations, simulation modelling and the development of a family of Injury Assessment Functions. The paper outlines the structure and progress of these activities, summarises the results and provides an overview of the optimiser model emanating from this research.