You are running a project which was budgeted based on some Rough Order of Magnitude $($ROM$).$ Meanwhile, with new estimates made on detail level and some work already finished, you found out that these estimates were consistently too low and the budget will not be sufficient to successfully run and finish the project. What should you do$?$

a$)$ Try to reduce scope or quality in areas where it cannot create difficulties for you and the team. Finally, it is not your responsibility that an insufficient budget has been created for the project.

b$)$ You shouldn't worry too much, It is quite normal that early estimates are too optimistic, later estimates are too pessimistic and the project costs will finally settle somewhere in between. So$,$ relax!

c$)$ Bring the issue to your sponsor and discuss how this should be handled. budgets will be reviewed and refined.