Cumulative calculation not returning data when no data for period selected

Hi nhuda 

Please try this:

First of all, add a new table:

Table = CALENDAR(MIN('vw_PRBI_Report_WeldRepairStats'[TestedDate]),MAX('vw_PRBI_Report_WeldRepairStats'[TestedDate]))

Then I've made some changes to your original measure:

Cumulative Tested = 
VAR _Select = SELECTEDVALUE(vw_PRBI_Report_WeldRepairStats[Project])
VAR _pStartDate = MINX(FILTER(ALL('vw_PRBI_Report_WeldRepairStats'),'vw_PRBI_Report_WeldRepairStats'[Project]=_Select),[ProjectStartDate])
VAR _toDate=MAXX(ALLSELECTED('Table'),'Table'[Date])

VAR __table = 
SUMMARIZE('vw_PRBI_Report_WeldRepairStats',[MaterialGroup],"__value",
    SUMX(
        FILTER(ALL('vw_PRBI_Report_WeldRepairStats'),
        'vw_PRBI_Report_WeldRepairStats'[TestedDate]>=_pStartDate && 
        'vw_PRBI_Report_WeldRepairStats'[TestedDate]<=_toDate &&
        'vw_PRBI_Report_WeldRepairStats'[Project]=_select && 
        'vw_PRBI_Report_WeldRepairStats'[MaterialGroup] = SELECTEDVALUE('vw_PRBI_Report_WeldRepairStats'[MaterialGroup]))
        ,IF(ISBLANK([Tested]) || [Tested] = 0, 0, [Tested])
    )
)
RETURN
IF(
    HASONEVALUE(vw_PRBI_Report_WeldRepairStats[MaterialGroup]),
    SUMX(
        FILTER(ALL('vw_PRBI_Report_WeldRepairStats'),
        'vw_PRBI_Report_WeldRepairStats'[TestedDate]>=_pStartDate && 
        'vw_PRBI_Report_WeldRepairStats'[TestedDate]<=_toDate &&
        'vw_PRBI_Report_WeldRepairStats'[Project]=_select && 
        'vw_PRBI_Report_WeldRepairStats'[MaterialGroup] = SELECTEDVALUE('vw_PRBI_Report_WeldRepairStats'[MaterialGroup]))
        ,IF(ISBLANK([Tested]) || [Tested] = 0, 0, [Tested])
    ),
    SUMX(__table,[__value])
)

Then use the 'table'[date] as a slicer:

The result is as follow:

Best Regards

Zhengdong Xu
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