Harry Blackmun, manager of the Dry Goods Department at Goodright's Grocery, has a budget of $6,000 per month for the current year. This budget includes the allocation of $500 of storewide common costs based on the square feet occupied by Dry Goods. Recently, Dry Goods expanded its total store space to include household items that had not previously been included in the store. During the current month, Mr. Blackmun was over budget by $700. The store manager was upset with the manager of Dry Goods and asked for an explanation.
What could be causing the budget overage? What budget tool could Goodright's use to better evaluate its department managers?