* 3 months ago *
Vendor: We screwed up and need to start the project from the scratch, this delays the project completion by a year.
Me: OK. Anything you need from me?
V: The good news is that you've given us all we need. Everything should be fine to submit and review by the end of March. (Deadline for 2018 completion is mid-April 2017)

* This week *
Vendor: We need this (partially unspecified) documentation urgently, and also we're missing these parts (~3 weeks effort).
All of which could've been started 3 months ago…