Why Are Projects Always Behind Schedule?

Instead we have to understand the distribution, and the mean as well, and add up how long it takes on average, rather than just in the most numerous case.

Further, and perhaps more importantly, by understanding each distribution, you have far greater knowledge about what the expected time will be, and where the delays are most probable; and you can begin to start analyzing where those delays might be coming from in the interactions of all the parts of the system. This is straight-up quality talk right out of W. Edwards Deming, and it's how you start to improve how you produce in general. Good stuff.

First, the industrial world also had significant issues with project definition and understanding. The problems were not already solved, and the process, inputs, outputs and the whole system was constantly changing. Every project was already about problem solving and scoping. So there's a bit of rose-colored glasses toward the past here.

Second, the idea that time estimation is no longer applicable is probably off. There are two separate problems: problem definition, and problem solving, and estimation is extremely useful in the latter. Problem definition is a different problem that still needs much focus, but it doesn't preclude the need for better understanding of time to coordinate other processes and dependencies. You might be saying that those dependencies aren't as important as we think, and I tend to agree, but that's a different argument.

Generally speaking, the idea that knowledge and skills from the industrial era are no longer applicable is untrue. There is a huge body of knowledge about how products are made and built that have 99% applicability to software and technology in the post-industrial world. This is because the problems are the same: management of people, leadership, understanding interactions within complex systems, understanding statistics (the importance of which this article proves profoundly), and improving the spread of knowledge. This is the way that Toyota began operating in the post-WWII era, the way W. Edwards Deming modeled companies, and the way that the current Lean movement guides you to improve almost any business. It's highly relevant.

The main point we should take away, is that time and estimates are not constraints on a system; but rather outputs that are predictable and follow statistical patterns. We can use those outputs to make better decisions, especially if we understand the whole process of production in a systemic way.

Estimation need not die. It's a tool for good in the hands of a systems thinker.

Improve the system, improve the world [cheap, fast, good] lives in. Still have to balance, but you're now balancing cheaper, faster, and gooder.

Another issue: It is really common for people to "take some well deserved time off!" when they finish some piece of the project earlier than anticipated, thus flushing away time that could have helped out on parts that will take longer than expected.

Cuz: Humans.

As an example: Arriving to the airport one hour in advance doesn't allow you to actually board a flight an hour earlier. But get to the airport one hour late — and you're flying tomorrow (or whenever the next flight is scheduled).