The simple A3 paper size - in the US we use 11”x17” – has become the go to instrument on Lean projects for design solution development and reporting, retrospectives, project dashboards and even proposals. At its most basic, the power of the A3 is that encourages (or enforces depending on how strictly managers adhere to the principles) a type of essentialism by requiring that all key information is laid out on a single sheet of 11x17 paper and is typically kept very visual.