Some great questions this morning!
Surprises in a project are very common. It’s pretty frustrating if you’re a few months into a proposal and someone says “oh by the way did you know…” and drops a bombshell. Grr!
The way you have to deal with these is to assess what that “surprise” really means for your project – If you can have a chat to a few people or hold a short meeting with the team you might be able to find a way to accommodate it with no significant impact. If not then the next key step is to communicate that change to people who need to know (i.e. the business area, specific engineers, the onsite plant team). Then you need to document this change to make sure it is very clear to everyone that there has been a change or addition to the project and to explain why. That way not only does everyone know, but you can learn from it next time.