Consider the following scenario: You are to oversee the project for a new textbook release for the fall semester. You've done something similar before, so you feel confident speaking with the stakeholders, project sponsor, and faculty director. You assure them the project will meet the 6-month deadline.

Around three months into the project, you notice that your writers consistently miss the writing deadlines you assign. Then you learn that a printer upgrade may delay printing the text books. Unfortunately, you forgot to include this delay in your time estimation. Now you have to tell the stakeholders that the project may not launch in time for fall.