Definition
Calculation of your Safety Stock, Target Stock, and Max Stock values is known as calculating Statistical Inventory Quantities, and act as inventory safeguards in StockIQ.
Statistical Safety Stock
Safety Stock is a number of units kept in inventory to guard against stock-outs. StockIQ calculates this using several factors, such as forecasted usage, lead time, desired service level, forecast error, EOQ, Lot sizing, and others.
Since we can never know the future, to guard against stocking out of a product, we carry an extra buffer of inventory known as safety stock. Your safety stock level is the lowest you ever plan your inventory to be.
StockIQ calculates safety stock in several ways. The two primary methods are standard statistical safety stock, and the second is an examination of the item's order arrival pattern, to see if demand spikes are significant enough to plan for in your stocking strategy. This is called Large Regular Pull safety stock.
When enabled, the greater of the two calculations is used for your safety stock setting.
Two additional methods for calculating safety stock are available, the Sporadic Safety Stock and Retrospective Safety Stock, but these are not commonly used.
Once a safety stock is calculated, StockIQ will also calculate Target Stock, and Max Stock levels, based off of the item's forecasted usage, forecast error, and a few other empirical factors.
Active Safety Stock vs Statistical Safety Stock
StockIQ will always calculate what it believes the safety stock should be, and this is displayed in the application as "Statistical Safety Stock", e.g, what StockIQ believes the safety stock should be.
In all cases, however, your safety stock settings control what Safety Stock is actually used. If you have a safety stock override in the system, that will be used instead of our default calculation, if that's what you have specified. For this reason, the active in-use safety stock is always displayed as "Active Safety Stock" so you can differentiate between the Safety Stock StockIQ is using for planning, and the raw calculated value.
If you have no overrides or other special rules in place, then the "Active" and "Statistical" safety stock values will be the same.