HALLIN AND HANSEN

 
The requirements and design phases are the most important steps in a (software) project. If these steps are not done right, the product quality is almost guaranteed to be low. It is good to perform these steps with paper designs to maintain a fluid, dynamic design methodology. Any computer investment activity (except prototyping) during the interval, including early coding, imposes a psychological restraint to change. Unrestrained change is necessary for a quality design.
- Hallin and Hansen