Days supply in excel - formula

[sasils]

Hi,

Need advise from the experts in this forum. Data is below

	W1	W2	W3	W4	W5	W6	W7	W8	W9	W10
Forecast	10	20	20	10	10	20	10	20	10	10
Closing stock	40	20	40	20	20	20	10	40	10	10
Week supply	2	1	3	1.5	1	1.5	0.5

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</tbody>

I would like to get a automatic calculation formulation for Week supply. For example. In Week 1 Week supply is 2 because of Week 1 closing stock can cover forecast for week 2 and week 3 (20+20) - 40 = 0, therefore it is 2.

However in Week 5 Week supply is 1.5 week because week 6 forecast is 10 and week 7 forecast is 20, closing stock in week 5 is 20, therefore week supply base on closing stock week 5 going forward is 1.5.

Hope this explains.

Cheers

Sasils

 

[kvsrinivasamurthy]

Does UDF will do.

 

[sasils]

Hi

Thank you, what is UDF?

Cheers.

 

[kvsrinivasamurthy]

UDF means user defined function. Function which we have to code. After coding it can be used like other function.

 

[sasils]

UDF means user defined function. Function which we have to code. After coding it can be used like other function.

Thank you, can you please help with the UDF coding?

Cheers.

 

[kvsrinivasamurthy]

Data is in A1:K3

Formula in B4 then drag across
=GetWeeks(B3,C$2:$K$2)

Code for UDF GetWeeks

Function GetWeeks(ClosingStock As Long, WeekRng As Range)


Dim T As Long


For T = 1 To WeekRng.Cells.Count


    If ClosingStock > WeekRng.Cells(1, T) Then
    GetWeeks = T
    ClosingStock = ClosingStock - WeekRng.Cells(1, T)
    
    ElseIf ClosingStock = WeekRng.Cells(1, T) Then
    GetWeeks = T
    Exit For
    
    Else
    GetWeeks = GetWeeks + Round(ClosingStock / WeekRng.Cells(1, T), 2)
    Exit For
    End If


Next T


End Function

Open tab Developer --> Visual Basic
IN VIsual Basic window

Insert --> Module

Now Paste the given code to module

Close the VB window

UDF is available in the function list like other functions.