What is the Deep-Dive Brainstorming technique?

Deep-Dive™ is the name of a technique used to rapidly immerse a group or team into a situation for problem solving or idea creation. This approach is often used for brainstorming product or process development.

Originally developed by the IDEO group (a learning design company) for rapid product development, the Deep-Dive technique is now widely and increasingly used for innovation not only in product development, but process improvement and customer service strategies. The method used by IDEO was documented by Andy Boynton and Bill Fischer (of International Institute of Management Development (IMD) business school), who latterly further enhanced the process and sold the rights to Deloitte Consulting in 2006.

What is the Deep-Dive Brainstorming technique?