Specification – Agreeing a development timeline and product attributes. Competitor analysis and definition of specific performance metrics.
Concept design – Initial ideas for the look and feel of a product.
Concept development – The addition of engineering detail. Turning preliminary CAD into 3D parts which fit together.
Prototyping – Physical exploration of the design and evaluation. How strong or heavy is it?, is it comfortable to hold, does a mechanism work?
Design development – Adjustments and control drawings.