It’s easy to believe that if we build solutions according to the principles, what we build will work. Certainly, that’s the case in many instances. But not, I suggest, when we’re talking about solutions for people? Why do we need to test and tune? Because we’re complex.
Materials, such as wood and steel have predictable properties. When you build a deck, you can follow the building codes for what you need to do for fixing posts to the ground, etc. However, people aren’t quite that predictable.
There’s a case to be made that the brain is the most complex thing in the known universe. In fact, we don’t fully know how it works! Thinking, then, that we can achieve a reliable change in the brain with simple mechanisms is kind of naive. We have to understand how the brain works, first, and then for complex changes, we need some detailed analysis and careful specification. However, we’re not done.
Once we’ve built it, we need to test and tune! Any solution isn’t guaranteed to be optimal or even effective, at least initially. Since people are complex, we can’t just design for the average (c.f. Todd Rose’s The End of Average). We can’t follow waterfall models, despite how appealing it is. Assuming we can is a path to boring and ineffective solutions. “If we build it, it is good” isn’t a useful assumption.
You see this in the best approaches. Michael Allen’s Successive Approximation (SAM), Megan Torrance’s Lot Like Agile Management Approach (LLAMA), David Merrill’s Pebble in the Pond, or Guy Wallace’s PACT approach (I’m not even going to try to deal with that acronym) all have iteration as a fundamental component.
You need some metrics, of course. You test against them, and then tune to get closer. The answer to “when do we stop iterating” is not “when we run out of time and money”. If you’re running out of time and money faster than you’re getting to your metrics, you need to explicitly consider some alternatives, like relaxing your goals, or investing more, or (horrors) abandoning where you’ve at. But it’s better to do it consciously!
To do this, we need to build ‘test and tune’ into our practices. We need to allocate time and money to it. Does this mean things will take longer and cost more? Possibly. The tradeoff is that we should be doing less courses overall, once we’re asking questions, and our solutions will be more effective. Going beyond knowledge dump courses that achieve no organizational benefit? I think that’s a fair exchange. I hope you do, too.