direct cost

direct cost can be linked directly to a cost unit.

say
a table requires 4 kg of wood to produce and cost of 1 kg of wood cost $5
so the cost of producing 1 table in terms of material should be (4×5)= $20

in case the store inventory consist of 2 kg wood at a rate of $5/kg
and 2 kg wood at a rate of $6/kg

in that case will the table cost in terms of material should be like (2×5)+(2×6)=10+12=$22

or it will be assumed that material cost per table is constant at $20