Many discussions of A3 reports in Lean omit one basic fact: A3 is a paper format. In millimeters, a A3 sheet is 297X420, roughly equivalent to 11×17 in inches. It is the size of two A4 sheets side-by-side, and half of an A2 sheet. The A-series of paper sizes is used all over the world, except in the US…
An A3 report is not just a story on one sheet of paper, but on one sheet of paper of this particular size, which has been found right to tell a manufacturing story with just enough details without turning into a victorian novel.
It can be posted on bulletin boards or above operator workstations. Operator instruction sheets are actually supposed to be on A3 paper.
Size does matter. If you shrink an A3 to A4 or letter size, it is no longer works as an A3, because the print will be too small for viewing on a board. If you show it on a PowerPoint slide, it is not an A3 either, because it does not have the permanence of hardcopy and, unless you have really advanced IT, you cannot annotate it manually.