Identifying Activity Bases in an Activity-Based Cost System Comfort Foods Inc. uses activity-based costing to determine product costs. For each activity listed in the left column, select an appropriate activity base from the right column. You may use items in the dropdown list more than once or not at all. Activity Cafeteria Customer return processing Activity Base Electric power Human resources Inventory control Invoice and collecting Machine depreciation Materials handling Order shipping Payroll Performance reports Production control Production setup Purchasing Quality control Sales order processing