This chart, from Growing Object-Oriented Software, Guided By Tests by Freeman and Pryce, shows ‘chaos’ vs time for two distinct project delivery methods (those which test early and those which test later).

Chaos vs Time

While the emphasis in their book is on the value of test automation and deployment pipelines (and they’re undoubtedly right in this regard), this principle of early feedback applies to other kinds of information relvant to quality, including exploratory testing, customer validation, security audits, and so on.

The fashionable term for this concept in software today is to “shift-left”. Managers of Lean production systems might instead speak of single-piece flow and jidoka to ensure fast feedback and continuous improvement. But the “time vs chaos” graph from the GOOS book is a particularly memorable image.