Starting with a design brief, a designer may come up with a good idea to solve a problem. Using an iterative design process, a model can be made from a design sketch and then tested against the criteria in the product specification. The test results may suggest failures and modifications required to the design. These changes are evaluated, and then the cycle begins again - until the best solution to the problem is found.
To help the designer arrive at the best solution, design ideas should be questioned and reviewed during the design process. This could include:
Designers use annotations to explain their sketches and models so that other people will clearly understand their design thinking. They also use annotations when communicating their design ideas to address design issues and approaches.