Life cycle assessment is not intended to exclude materials, but is a true tool for improvement of car design. The aim of life cycle assessment is to optimize a car design according to functional, economic, and environmental criteria. The complete life cycle of the car is taken into account in the investigation including production of materials and the vehicle; use of the vehicle, which takes into consideration its production and consumption of fuel; and recovery at the end of the vehicle's life. The design's function is to 'provide a self-powered vehicle for transportation of four people and their luggage for one year'.