Software and web engineering practices vary widely from organization to organization, and it follows that the approaches used for planning and integrating design vary as well. In all cases, everyone should be clear on the answers to the following questions. Any reasonable design process has clear answers to them, and any reasonably good design team should have complete awareness of the answers. References on creative thinking Lateral thinking , by Edward De Bono Education on the nature of critical thinking. Full of exercises and techniques for applying better thinking practices to many different situations.
Many examples have direct applications to design problems.
The Universal traveler , Don Koberg Handbook of creative thought and behavior. The book covers a wide range of philosophical and pragmatic ideas, and is a fast read. Many references to other resources. This one is a gem. An industrial designer offers his best practices and philosophies.