We review the control theoretic approaches made to solving aggregate produc
tion-inventory problems, highlighting some of their common failings. One of
these is the inability to realistically model batch production costs. By a
pplying a novel optimal control algorithm to a differential equation model
of a production-inventory system we successfully mimic these cost structure
s and find optimal responses to fluctuations in demand. We then examine how
the various penalty costs qualitatively affect the response of the system.
The second part of the paper deals with the supply chain phenomenon of dem
and amplification, the tendency of small fluctuations in demand at the reta
iler end of the supply chain to be amplified as they are communicated down
the chain. By considering our production-inventory system to be part of a s
upply chain we examine the effect of batch sizes on demand amplification un
der the assumption of the rational behaviour of supply chain players. (C) 2
001 Elsevier Science B.V. All rights reserved.