Inventory Forecast Recursive Calculation

Hello,
I'm the user from this topic, replying to your PM. Indeed it looks like the problem i was having. It took steps but I think I managed to get what you needed ?

1. Create the date MEASURE 

get date = max('DateTable'[Date])

2. Create the Sales At Date MEASURE (everything will be done by measures, not calculated columns) 

SalesAtDate = calculate(sum(Table2[Sales Forecast]);filter(Table2;Table2[Month]=[get date]))

3. Same for Inventory :

InventoryAtDate = calculate(sum(Table2[Inventory]);filter(Table2;Table2[Month]=[get date]))

4. Create the measure of inventory per month 

Inventory In Month = 
	Calculate(
		sumx( values('DateTable'[Date]); [InventoryAtDate]);
		datesbetween(
				'DateTable'[Date];STARTOFMONTH('DateTable'[Date]);ENDOFMONTH('DateTable'[Date])))
	

5. And its last non blank value : 

Inventory Last non blank = LASTNONBLANK(Feuil1[Inventory];1)

5. Create the measure with the sales per day for days where there is no inventory data : 

Sales Last Non blank = if(isblank([Inventory In Month]);[SalesAtDate];blank())

6. And sum this measure (that way it will not start from january, it will start as soon as you don't have an inventory)

SalesCumulative = 
	Calculate(
		sumx(values('DateTable'[Date]); [Sales Last Non blank]);
		datesbetween('DateTable'[Date];bLANK();max('DateTable'[Date]))
	)

7. The forecast is the substraction of Cumulated sales from the last inventory date and the last inventory

Inventory Forecast = if(isblank([Inventory In Month]);CALCULATE([Inventory Last non blank] - [SalesCumulative]) ;[Inventory In Month])

 Hope that does the trick. It is surely not the best way to do it, i'm still new at this.

Cheers