eBook Calculating and Using Dual Charging Rates The expected costs for the Maintenance Department of Stazler, Inc., for the coming year include: Foxed costs (salaries, tools): $77,400 per year Variable costs (supplies): $1.3 per maintenance hour The Assembly and Packaging departments expect to use maintenance hours relatively evenly throughout the year. The Fabricating Department typically uses more maintenance hours in the month of November. Estimated usage in hours for the year and for the peak month is as follows: Yearly hours Monthly Peak Hours Assembly Department 4,200 210 Fabricating Department 6,300 1,260 Packaging Department 11.000 630 Total maintenance hours 21,500 2.100 Actual usage for the year by Assembly Department 3,250 Fabricating Department 6.400 Packaging Department 10,200 Total maintenance hours 19,850 Required