Date Difference between 2 Columns

[Anonymous]

Hello,
I have a 2 table with
table A contains Start & End dates as of which i need to calculate the difference between them
Table B contains 2 other columns which i need to use as a filter.

The dax formula used is as below, but the result is far from right (it should give me only around 21 weeks but it is giving me 72 weeks

No.of Fabrication Weeks =

VAR SelectedActivityDescription = SELECTEDVALUE(ActivtiyLevelProgress[ActivityDescription])

VAR SelectedCustomText01 = SELECTEDVALUE(Equipment[CustomText01])

VAR TotalDuration =

    CALCULATE(

        SUMX(

            Equipment,

            IF(

                Equipment[CustomText01] = SelectedCustomText01,

                DATEDIFF(Equipment[InstallationStart], Equipment[InstallationEnd], WEEK)

            )

        ),

        FILTER(

            ActivtiyLevelProgress,

            ActivtiyLevelProgress[ActivityDescription] = SelectedActivityDescription &&

            ActivtiyLevelProgress[Progress] = 100

        )

    )

RETURN

    TotalDuration

Sample Dataset
Sample Dataset 

what did go wrong in the Dax formula ?

[some_bih]

Hi @Anonymous without model, it is hard to spot what could be wrong. Still, please check FILTER part of CALCULATE (ActivtiyLevelProgress[Progress] = 100)

[Anonymous]

The model size is big and contains alot on confidential data.
I have uploaded a sample of the Data in excel in the orginal post,kindly check if you can please.