Design Sprint

The sprint is a five-day process for answering critical business questions through design, prototyping, and testing ideas with customers.

https://en.wikipedia.org/wiki/Design_sprint

The Sprint book http://www.thesprintbook.com/ by Jake Knapp and John Zeratsky. ISBN:0593076117

Michael Sueoka: How we completed a 5-day Design Sprint in 3 Days.