The article was doing pretty well until they brought up historical data. The exact same software project done twice can take wildly different times because the

The article was doing pretty well until they brought up historical data. The exact same software project done twice can take wildly different times because the team and/or the requirements are different. That's the whole point of Agile, you need regular interaction with a customer to slowly build the software to a state they are happy with. And they should keep paying for the work until it is done or accept whatever state was delivered by the time the budget ran out. If that is not how you are doing Agile you have missed the point. It is not possible to predict software development because unlike a bridge the requirements are never fixed and there are too many unknowns. If you get your requirements fixed at the start, they never change, and you are not going to suddenly have to deal with some library/framework change in the middle of everything, then you can estimate, but you are not doing the software development 99% of the world is.