The purpose of this study was to find an analytic solution
for the optimal capacity of a batch-storage network that meets the
demand for finished products under sporadic operating time losses.
Batch processes are prone to random but infrequent operating time
losses. Two common remedies for such failures are the duplication
of the process and increases in the process and storage capacity,
which are both very costly. A model that minimizes the total cost,
which consists of setup and inventory holding costs as well as the
capital costs of constructing processes and storage units, has been
developed by using the framework of a batch-storage network with the
flows that are susceptible to sporadic operating time losses. A graphical
analysis for the estimation of the upper and lower bounds of the flows
under sporadic shutdowns is used in this approach. The advantage of
our model is that it provides a set of simple analytic solutions in
spite of its realistic description of the material flows between processes
and storage units.