A common misconception is that Agile development processes are faster. I’ve heard this from leaders as a justification for adopting Agile processes and read it in proposals as a supposed differentiator. It’s not true. Nothing about Agile magically enable teams to architect, engineer, design, test, or validate any faster.
In fact, many parts of Agile are actually slower. Time spent on PI planning, backlog refinement, sprint planning, daily stand-ups1, and retrospectives is time the team isn’t developing. Much of that overhead is avoided in a Waterfall style where the development follows a set plan.
What Agile does offer, however, is sooner realization of value. And that’s the source of the misconception. The charts below illustrate this notionally. You can see that Agile delivers a small amount of system capability early on and the builds on that value with incremental deliveries. By contrast, Waterfall delivers no system capability until the development is “done”, at which point all of the capability is delivered at once. Agile development isn’t faster, but it does start to provide value sooner; that adds up to more area ‘under the curve’ of cumulative value.
But, that’s not even the real value of Agile, in my opinion. On the charts you’ll also notice two different Waterfall lines, one for theory and one for practice. In theory, the Waterfall requirements should deliver the exactly correct system. In practice, requirements are often poorly written, incomplete, or misinterpreted, resulting in system that misses the mark. It’s also possible for user needs to change over time, especially given the long duration of many larger projects.
But because validation testing is usually scheduled near the end of the Waterfall project, those shortcomings aren’t discovered until it’s very costly to correct them. With Agile, iterative releases mean we can adapt as we learn both on an individual feature level and on the product roadmap level.
In short, Agile isn’t faster. But it delivers value sooner, delivers more cumulative value over all, and ensures that the direction of the product provides the most value to the user.
For more, check out my series on Agile Systems Engineering. Also, share your thoughts on the differences between Agile and Waterfall in the comments below.
- Don’t get me started on managers who insist on large, long stand-ups where nobody actually stands, totally defeating the point