In the past 4 years I have been working for the same company and my team delivered around 20 or so projects and didn’t miss a single deadline.

Before that, in previous companies, the same thing happened. Lots of projects and no missed deadlines.

I believe it’s due to a simple thing: expectations.

Project expectations must not be around specific implementations or features, but around problems solved.

That gives the project team room to learn and adapt to changing conditions which is especially valuable when you are doing something for the first time.

For the customer, that is having his problem solved, it doesn’t matter if a button is white or blue or if it is actually a button. It matters that a specific problem gets solved when it needs solving.

Everything in addition to that is waste.