The design process
A common way to split up the design process is:
Idea phase
Generating wild ideas, emphasis on creativity, brainstorm. Exploring unsuspected possibilities
Concept phase
Translating ideas into designs, filtering on practicality. Resulting in a few possible designs. Sketchy.
Design phase
Working out the chosen direction. Resulting in a very tangible product design
Engineering phase
Complete and accurate detailing of the entire design. Solving any and all technical and production issues.
Pre-production phase
Testing all the production equipment. Sorting out any issues that may arise.