Welcome to Part 4 of a 5-part series on Lean Design. In Part 1 I made the case that the achievement of “flow” is a major goal in the design of a Perfect Value Stream, and in Part 2 I discussed different ways to measure flow and why this is important. In Part 3 I gave you a quick introduction to the design methodology itself. In this lesson I’ll continue that discussion with five hurdles that will need to be incorporated in your design to create the Perfect Value Stream.