Albert Einstein famously said, “Insanity is doing the same things, the way you’ve always done them, and expecting different results.” Thus, to get different (and better) results, you’ll need to make changes, right? Easier said than done for most builders. Inertia is hard to overcome. Over the course of the 200+ Lean Process implementations my TrueNorth colleagues and I have led over the years, there are many sources of product and process waste we see repeatedly, at nearly every builder we encounter. The severity and frequency vary, but these forms of waste pop up again and again, even outside of the US. For this column I’ve compiled a list of the 20 most common “repeat offenders” we have found over the past decade.