The allocation of fixed production overheads to the costs of conversion is based on the
normal capacity of the production facilities. Normal capacity is the production
expected to be achieved on average over a number of periods or seasons under normal
circumstances, taking into account the loss of capacity resulting from planned
maintenance. The actual level of production may be used if it approximates normal
capacity. The amount of fixed overhead allocated to each unit of production is not
increased as a consequence of low production or idle plant. Unallocated overheads are
recognised as an expense in the period in which they are incurred. In periods of
abnormally high production, the amount of fixed overhead allocated to each unit of
production is decreased so that inventories are not measured above cost. Variable
production overheads are allocated to each unit of production on the basis of the actual
use of the production facilities.