On The Imaginary Trade-Off Between Agility & Rigour

In 2009, I co-authored a paper titled Formal vs. Agile: Survival of the Fittest, in which I argued that rigour and agility in software engineering were not antithetical. I first had to explain to my co-authors that Agile Software Development was not the same thing as Rapid Application Development, which was an ironic pointer to where the perception of an apparent conflict might come from, at least in academia. That misunderstanding may explain much of the myth that agility lacks rigour. But in my career, I’ve also come up against another misunderstanding about rigour itself. To me, when you talk about “rigour” in software engineering, it conjures up images of guided inspections, static analysis, model checking, proof assistants, contracts, property-based testing, exhaustive testing of constrained state spaces, etc, being performed on small batches of changes in tight feedback loops. I know from first-hand experience that teams can apply this level of rigour in a highly iterative,…