In-Process Inventories

Many manufacturing operations can be looked upon as chains of operations separated by inventories. In any real case, there is a question about how inventory investment should be balanced between these various in-process inventories. Investigation of this situation for a very general control system—the base-stock system—leads to some general results which enable one to answer this question by examining a (generally small) finite number of possibilities. The conclusion may be stated “The service time for any inventory should be zero”. An important corollary of the method is that it answers the question of what points in the manufacturing operation should be inventory points and what points should not.