If you’re working with a good team, expect for people to make their deadlines most of the time, but definitely not all the time. People will get sick, get hurt, have bad days, and sometimes just not be able to work that day because they can't focus. It's just the way people are, so don't expect to meet all your deadlines all the time. It just doesn't happen that way. Keep your eyes on the timelines and don't let them start slipping, but don't expect to meet every deadline either.