I do think that a pathway such as the one you mentioned is followed most of the time. However, no matter how hard you try there will always be delays. From personal experience, our team was providing electrical power to a community far from the city in my original country. We planned everything to the point that the utility poles would be placed next to the main street that connects the community. When we were about to execute the project, a big flooding occurred which made a river close to the community disappear the main street and therefore the project was initially where we started. We had to change our schedule and location of the utility poles. It took us way longer than what we planned. We never thought a natural disaster such as that would occur, but it did. I think we as engineers have to accept that something delays are cause for reasons that are out of our control, but they key is how we respond to those delays, with responsibility and good quality work.
Let me know what you think.

Sincerely,
Roberto Pineda.