How the System Calculates Order Point Safety Days

The system calculates safety days for each product's order point, based on lead time and the following equations:

How the System Calculates Base Order Point Safety Days

The system first applies an inverse relationship to the length of the lead time and the number of safety days. That is, for shorter lead times, the system recommends more safety stock to protect customer service levels. For longer lead times, the system recommends less safety stock to protect against carrying costs on the extra inventory.

For base Order Point Safety Days, three equations apply:

If the Lead Time is...

The base Order Point Safety Days is...

The formula is...

less than 15

0

If LT < 1, then LTSD = 0

greater than 1 up to 15

the lead time plus seven days multiplied by the hits related safety coefficient with the result added to the lead time.

If LT 1 to 15, then LTSD = ((LT + 7) * HRSC)

greater than 15 but less than 60 days

one half the lead time plus 15 days multiplied by the hits related safety coefficient with the result added to the lead time.

If LT 16 to 60, then LTSD = ((LT/2) + 15) *HRSC

greater than 60

the lead time divided by 4 plus 30 days multiplied by the hits related safety coefficient with the result added to the lead time.

If LT 61 or higher, then LTSD = ((LT/4) + 30) *HRSC

How the System Adjusts Base Lead Time Safety Days by the HRSC Factor

The system next adjusts the base lead time safety days to consider whether the item is a fast-moving, high demand item or a slow-moving, low demand item using the Hits Related Safety Coefficient (HRSC) factor. This adjustment enables the system to compensate for the relative unreliability of demand forecasting for slow-moving items compared to fast-moving items.

The system uses the following equation:

( ( 4 / Total Hits on Product in Last 365 Days) + 0.6 ) * Safety Factor

The result of this equation displays in the Hits Adjusted SF field on the Product Order Points/Line Points window. You can change the HRSC by changing the Safety Factor (SF) field on the Product Order Points/Line Points window. The default value is 1.0. If you update your service levels on the Product Order Point/Line Point window, then the HRSC factor also changes.

See Also:

Reviewing Product Order Points and Line Points

How the System Calculates Line Point Safety Days

Order Points and Line Points Overview