Patent ID: 8140396

Claim:
A safety stock amount calculation method that calculates a safety stock amount SS based on a demand deviation σ for a certain commodity, an inventory adjustment period N being calculated from a lead time L of the commodity or its components and a safety coefficient k that denotes the level of a ratio of service S for demand, the method comprising: storing, in a storage unit that includes a non-transitory computer-readable recording medium, a safety stock amount calculation program executable by a processor; calculating, using the processor, a probability Pb that a delivery time for the commodity required by a customer is shorter than the lead time L; calculating, using the processor, any of an average value, median, mode, experimental value of the difference between the lead time L and the customer's required delivery time, and a value obtained by subtracting the minimum value of the customer's required delivery time from the maximum value of the lead time L as a representative value LL of the difference between the lead time L and the customer's required delivery time in the case where the lead time L has exceeded the customer's required delivery time; correcting, using the processor, the inventory adjustment period N to the representative value LL or the value obtained by adding an ordering cycle M for the commodity to the representative value LL; and calculating, using the processor, the safety stock amount SS based on the standard deviation σ, corrected inventory adjustment period N, probability Pb and safety coefficient k.