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 Calculation of Days' Supply

Use

The key figure Days' Supply displays how long the projected stock of a period would be sufficient to cover the demands of the subsequent periods, if no receipts were to occur in these periods. The demand of a period is the sum of the key figures from the profile for projected stock that represent a demand (a quantity with a minus sign). The system only considers demands in the display period of the replenishment monitor.

The days’ supply is specified in days. The value 9999 indicates an "endless“ days' supply. This means that the projected stock of a period is larger than the sum of the demands in the display period of the replenishment monitor.

For more information about the profile for the projected stock, see Calculation of Projected Stock .

Example

The following table shows a section of the planning grid with the key figures Demand , Projected Stock , and Days’ Supply . The planning horizon displayed comprises five periods. Each period lasts one day.

Key Figure

Day 1

Day 2

Day 3

Day 4

Day 5

Demand

10

20

40

10

100

Projected Stock

38

138

18

8

-2

Days’ Supply

1.45

2.88

1.08

0.08

0

The system calculates the days’ supply as follows:

  • Days' Supply on Day 1

    The projected stock of 38 at the end of the first day is sufficient to completely cover the demand of 20 for the second day. The rest of the projected stock, 18, can only partially cover the demand for the third day. It can only cover 45 percent (18/40 = 0.45). The days’ supply on the first day is therefore 1.45 days.

  • Days' Supply on Day 2

    New planned receipts or stocks are received on the second day (this information is not displayed in the table), so that the projected stock at the end of the second day is 138. This is sufficient to completely cover the demand for the third and fourth days (40 + 10). The remaining 88 planned receipts or stocks are sufficient to cover 88 percent (88/100 = .88) of the demand of 100 on Day 5. The days' supply on the second day is 2.88 days.

  • Days' Supply on Day 3

    At the end of the third day, the projected stock is 18. This is sufficient for the fourth day and for eight percent of the fifth day. The days’ supply is therefore 1.08 on the third day.

  • Days' Supply on Day 4

    At the end of the fourth day, the projected stock is eight. Thus, eight percent of the demand for the fifth day (8/100) can be covered. The days’ supply is therefore 0.08 on the fourth day.

  • Days' Supply on Day 5

    At the end of the firth day, the projected stock is below zero and cannot therefore cover any demands in the subsequent periods. Therefore, the days’ supply is zero.