☛ Are you using statistical formulas that incorporate the accuracy of sales forecasts, required production lead times, manufacturing schedule adherence and service-level data for each SKU?

☛ Or are you using a simple rule of thumb such as "all products made in factory ABC need 15 days of safety stock."

The problem with the rule-of-thumb approach is that typically it's based on products with the most uncertain delivery histories. Efficient operations use a standard statistical formula that looks at historical data for individual products.