When designing, the problems that we deal with are usually big, nebulous and messy, making it hard to maintain an overview. Problems may have a variety of conflicting and contradictory constraints, which means that sometimes solving one part of the problem can cause issues with another. Balancing all these diverse concerns in your head at once can be a challenging task, and it is difficult – if not impossible – to solve the entire problem at once.
Continued on pages 112-113 of Design. Think. Make. Break. Repeat.