Prototype Development & Evaluation
What Is a Prototype?
A prototype is a working model or test version of a product. In AQA Design & Technology, the term can describe either a physical product or a system (such as an electronic circuit). Prototypes allow designers to test ideas in the real world, identify problems, and refine their designs before committing to full-scale manufacture.
Developing Prototypes
The specification states that prototypes must be developed in response to client wants and needs. A successful prototype should satisfy the requirements of the design brief, respond to what the client has asked for, demonstrate innovation, be functional, consider aesthetics, and be potentially marketable.
A well-developed prototype must: (1) satisfy the requirements of the brief, (2) respond to client wants and needs, (3) demonstrate innovation, (4) be functional, (5) consider aesthetics, and (6) be potentially marketable.
Designers use different types of prototype depending on what they need to test:
- Appearance models — show the form, colour, and surface finish of a product but may not be functional. Often made from foam, card, or 3D-printed materials.
- Functional prototypes — work as intended, allowing the designer to test mechanisms, circuits, or moving parts. They may not look like the final product.
- Production prototypes — closely resemble the final product in both appearance and function. Used for final testing and client approval before manufacturing begins.
Rapid prototyping uses technologies like 3D printing (additive manufacturing), laser cutting, and CNC machining to produce physical models quickly and cheaply. A designer can go from a CAD model to a physical prototype in hours, test it, modify the digital file, and print an improved version the same day. This dramatically speeds up the iterative design process.
CAM (Computer Aided Manufacture) uses CNC (Computer Numerical Control) machines that read digital design files and cut, shape, or build components with high precision and repeatability. In combination with CAD, this enables a seamless digital workflow from design to manufacture.
Evaluating Prototypes
Evaluation is a continuous process, not just a final step. The specification requires students to evaluate prototypes by reflecting critically on their work, responding to feedback, suggesting modifications, and assessing fitness for purpose.
AQA expects you to: (1) reflect critically on your prototype, responding to feedback; (2) suggest modifications to improve it through inception and manufacture; and (3) assess whether the prototype is fit for purpose.
Testing Against the Specification
The design specification written during the investigation stage becomes the evaluation checklist. Each criterion — dimensions, weight, materials, function, aesthetics — is tested against the prototype. Where the prototype falls short, the designer identifies what went wrong and proposes specific improvements. This testing-and-improvement cycle continues until the product meets all specification requirements or the best possible compromise is reached.
Client & User Feedback
Effective evaluation includes feedback from the client and target users, not just the designer’s own assessment. This might involve user testing sessions, questionnaires, or interviews. Third-party feedback often reveals issues the designer has overlooked — for example, a handle that feels comfortable to the designer might be too small for users with larger hands.
Testing with real users reveals problems the designer may not notice. Third-party feedback is essential because the designer is too close to the project to be fully objective.