Trimake Limited makes three main products, using broadly the same production methods and equipment for each. A conventional product costing system is used at present, although an activity-based costing (ABC) system is being considered. Details of the three products for a typical period are:

Direct labour costs £14 per hour and production overheads are absorbed on a machine hour basis. The rate for the period is £28 per machine hour.
(a) You are required to calculate the cost per unit for each product using conventional methods.
Further analysis shows that the total of production overheads can be divided as follows:
(%)
Costs relating to set-ups .................................. 35
Costs relating to machinery............................... 20
Costs relating to materials handling ................... 15
Costs relating to inspection ............................. 30
Total production overhead 100%

The following activity volumes are associated with the product line for the period as a whole.
Total activities for the period:

You are required
(b) to calculate the cost per unit for each product using ABC principles;
(c) to comment on the reasons for any differences in the costs in your answers to (a) and (b).

Hours per unit Materias Labour Machine per ui olumes hours unit Units Product X Product Y Product Z 1% 1 1 1 3 20 12 25 750 1250 7000 Number of set-ups Number of movements of materials Number of inspections Product X Product Y Product Z 75 115 21 8 120 1000