Fourth, vertical integration can pose problems of balancing capacity at each
stage in the activity-chain.
The most efficient scale of operation at each step in
the chain can vary substantially.
Exact self-sufficiency at each interface is the
exception not the rule.
Where internal capacity is deficient to supply the next
stage, the difference has to be bought externally.
Where internal capacity is
excessive, customers need to be found for the surplus. And if by-products are
generated, they must be disposed of.