How to utilize previous lines record for next lines computation

Hi, 9mikejacobs 

Here are the steps you can follow to achieve

1. sort the YearWeek column
2. create an index column in the power query editor, you can follow this picture:

3.create measure for Inventory Rolling

Inventory Rolling = var _index=MAX('Table'[Index])

var _inv=CALCULATE(sum('Table'[ Inventory ]),FILTER(ALL('Table'),'Table'[Index]<=_index))

var _poq=CALCULATE(sum('Table'[ PO Order Qty ]),FILTER(ALL('Table'),'Table'[Index]<=_index))

var _ooq=CALCULATE(sum('Table'[ Open Order Qty ]),FILTER(ALL('Table'),'Table'[Index]<=_index))

var _odq=CALCULATE(sum('Table'[ Open Deliveries Qty ]),FILTER(ALL('Table'),'Table'[Index]<=_index))

return _inv+_poq-_ooq-_odq

4.create measure for inventory:

Inventory = var _inv=CALCULATE([Inventory Rolling],FILTER(ALL('Table'),'Table'[Index]=MAX('Table'[Index])-1))

return if(ISBLANK(_inv),CALCULATE(MAX('Table'[ Inventory ]),'Table'[Index]=1),_inv)

And you can get your expected chart like this:

Best Regards,

Robert Qin

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