In this paper we study a system of n machines in series. Each pair of subsequent machines is separated by a finite buffer. The machines are unreliable and can break down. In such a production system, the allocation of buffer space between successive stages in the system is of capital importance since it has a significant influence on the availability of the system. We examine how the allocation of buffers can be expressed as a non-linear optimisation problem in which the total cost of installing and using the buffers is minimised. Some of the assumptions of this approximation model are also examined.
