Days Of Supply (DOS)

Question

All,
One of the SAP's xApps Analytics Composite Applications for SCM included in 2004s is the Global Inventory View. One of the metrics offered within the application is the actual Days of Supply (DOS).  From documentation I see that it is displayed by query 0APO_C12_Q0001 that reads from InfoCube 0APO_C12. I don’t have access to the live 2004s system.
Who knows how 2004s determines the DOS value. In release 3.5 the DOS was available in two objects in Business Content:
MultiProvider 0IC_MC02 - Material Range of Coverage Components
The MultiProvider 0IC_MC02 is a union of Material Stocks/Movements (0IC_C03) and Plan/Actual Comparison Material Consumption (0PP_C05).
You can display the number of days during which the current stock of materials will cover future requirements based on the current requirement from production. When calculating the material range of coverage, it is assumed that the average future requirements for production components will be the same as those in the past (constant model). The key figure is determined on the basis of the average production requirements in the last 365 days calculated from the current calendar day.
(0IC_C03) - Material Stocks/Movements (Inventory InfoCube)
You can use this InfoCube to show on the basis of the stock and issue values the number of days during which the current stock will cover future stock issues.  When calculating the material range of coverage, it is assumed that the average future stock issues will be the same as those in the past (constant model).  The key figure is determined on the basis of the average stock issues in the last 365 days calculated from the calendar day selected. 
What I would like to know is whether the Days Of Supply offered by the  2004s is the actual DOS that takes into account the impact the demand and supply have on the inventory on-hand?
Thanks in advance,
Stan

Answer 1

Hi David,
Thanks for the tip on Code Tags. 
The logic for Days of Supply is to take the ending inventory (Stock on Hand) for the month then looking forward at the forecast for future months determine the Days of Inventory on Hand (Days of Supply).
In the example Stock on Hand for May is -23 and Days of Supply is 0
However for June 2011, Stock on Hand is 442 so it has coverage for all the days in July (31) and then it can cover an additional day in August so Days of Supply is 32.
The code I placed in original question is just an example of how it could be calculated in Excel.
We would like to create the report in WEBI but we know longer can use Macro's in the version we are rolling out.
Here is the Excel Function I created for Days of Supply:  This will give you the code to acheive the narrative I stated above.
It passes Stock on Hand then two arrays.  The forecast for future periods and the number of days in each respective period.
Private Function DOS(EndInventory As Single, Forecast As Variant, Days As Variant) As Single
    DOS = 0
    TotalDays = 0
    InventoryVar = EndInventory
    For x = 1 To Days.Count
    TotalDays = TotalDays + Days(x)
    Next
    For i = 1 To Days.Count
    If InventoryVar > 0 Then
        If Forecast(i) = 0 Then
            DOS = DOS + Days(i)
        Else
            If InventoryVar < Forecast(i) Then
                DOS = DOS + ((InventoryVar / Forecast(i)) * Days(i))
            Else
                DOS = DOS + Days(i)
            End If
        End If
    Else
        Exit For
    End If
    InventoryVar = InventoryVar - Forecast(i)
    Next
If InventoryVar > 0 Then
    DOS = 9999
End If
End Function