Please give me 2 short answers. Thank you

I held the title of Financial Analyst at several companies and one of my most important duties, after preparing the budget, was to monitor results. I had to do 'budget vs. actuals reporting by department on a monthly basis. Department managers then had to prepare explanations for variances -- both favorable and unfavorable. What are some of the benefits of doing this monthly process? How do we use the results of the budget vs. actuals analysis? Sabarte