BE9,12- Using Excel with Time-Driven Actgivity-Based Costing PROBLEM Martha Motors was evaluating its costs related to customers checking cars in and out for maintenance. Previously, it calculated an activity-based rate for each customer for this process that included both check-in and check-out. A new timedriven study recognized that the practical employee capacity was lower than the theoretical capacity; it further determined estimated times for check-in separate from check-out. Information on the rates and times of the activities is presented here