Preliminary prototyping captures basic form and functionality using methods like 3D printing or assembling existing components. Functional testing ensures the prototype meets specifications and identifies design flaws or improvements. Usability testing evaluates user experience, ease of use, and gathers feedback for improvement. Performance testing assesses durability, reliability, speed, and efficiency. Iterative refinement incorporates feedback, making adjustments until desired functionality and user experience are achieved. Market evaluation assesses potential demand and aligns the product with market requirements before final prototype development and preparation for production.