What do you do when your team misses a deadline?

What's Really Going On: Your team blew a deadline. What's usually behind it?

The estimate was optimistic from the start. The planning fallacy: people underestimate time even with past experience. Source: Wikipedia – Planning fallacy

What To Do: What should you do?

Run a blameless review and use past projects to estimate next time. Reference-class estimates beat gut feel. Source: Wikipedia – Reference class forecasting

Why It Works: Why does it work?

It fixes the system, not a scapegoat. Blame hides problems; blameless reviews surface them. Source: Wikipedia – Postmortem documentation