Part-time mechanical design engineers examine the products and processes of manufacturing firms and develop new and improved methods of production and management. Unlike full-time employees, part-time mechanical design engineers work typically work thirty hours or less a week. As a part-time mechanical design engineer, you study a company's current product designs and assembly methods and find ways to improve efficiency in the process and make the product more effective in its use. Most mechanical design engineers use computer-aided design (CAD) software to create 3D prototypes to run through the new processing steps. They follow each stage of production, making modifications as they go, and also inspect the final product to ensure it meets company and government standards. A part-time mechanical designer may work for a specific company or work freelance as an independent contractor.