The whole point of agile has always been to be lightweight, pretty much by definition (read the Agile Manifesto). If it feels oppressive or constricting, you're

The whole point of agile has always been to be lightweight, pretty much by definition (read the Agile Manifesto). If it feels oppressive or constricting, you're either doing it very wrong (every good thing can be perverted into its opposite) or need to get over your primadonna issues. By "formal", I just mean that there's a written process for what to do when that everyone follows as long as they do not have a very good specific reason to deviate from it (and if that happens too often you try to find the reason and fix it, possibly by adjusting the process). Things that make a big difference to me: continuous integration. Time-boxed releases focused on fully-working incremental business value. Regular reviews of the process itself. Rigid rules for what should and should not be discussed in meetings (at least the recurring all-hands ones). Measurable differences? No, just heaps of anecdotal evidence. There's damn little quantifiable evidence for anything at project scale, no matter which industry, probably because differences between projects are so large and controlled experiments at that scale almost impossible.