Slow Moving Logic
Items with little (or no) activity are known as "Slow Moving" or "No Moving" items.  These are often found in maintenance inventories such as those in public utilities.  These can be large and expensive.  They can be small and inexpensive.  They are often critical and must be available in case of emergency.  An inventory planner knows that there will be some demand, but has no idea when or exactly how much will be needed.  As you might expect, these items usually have no forecast.  Instead, SMS will predict how many will be needed and store that number as a safety stock.  For example, there may be 20 generators in use and each costs $10,000.  Storage of five (5) for emergency use would be an expensive capital investment.  Storage of only one (1) may result in a critical outage of two (2) at the same time.  SMS determines the proper "spares level" to stock based on past usage (if any), MTBF rates, "number in service" and criticality (i.e., service level).  This is automatic and can be done along with more active items.  This logic keeps a portion of the average annual usage based on criticality (i.e., service level) then factors it up (or down) based on lead time.