Let’s just say you’re driving down a country road. After a while the road ends at a river. There are some construction engineers building a bridge across the river to connect to a road on the other side of the river. You ask the engineers “when will the bridge be finished?”. They reply “in 2 weeks”. So you say to them “OK, but I told my client that I will drive over the bridge tomorrow, so I’m going to come back here tomorrow and drive over the bridge, whether it’s finished or not”. Why is that not acceptable in construction engineering but standard practice in software engineering?