The underground mining environment places harsh demands on equipment. As a result, vehicle efficiency is compounded by the complexity inherent in designing high capacity and durability into a minimum size package. Invariably these problems are made more difficult by the nature of underground applications which demand a great variety of customizing of machines to fit specific operations.In view of this background, a better approach to the development of a new or improved machine would be to provide the engineering staff with guidelines which meet durability and minimize complexity. At the same time these guidelines should reduce the requirement for specific machine customizing. The guideline process should establish realistic targets for optimization of gross vehicle weight, parasitic losses, and power train matching. Computer simulation of gradeability and retardation help identify potentially fruitful areas for design improvement. Matching of engine displacement with torque converter, transmission characteristics and axle gearing, permits minimum size engine selection consistent with guideline targets. It is concluded that the methods employed make possible a high level of design and component selection which maximizes machine performance and minimizes complexity.