The team has decided to move forward with the company luncheon in the timeframe established

The team has decided to move forward with the company luncheon in the timeframe established. You are about two weeks from the event, and there has been little to no management oversight on the performance of the project.  

• Why is it necessary to track actual and committed costs once a project starts?
• Why is it necessary to calculate the earned value of work performed?
• Why are the cost control steps important to the project?

Please be sure to validate your opinions and ideas with citations and references in APA format.