Calculation on Matrix Values (Matrix Value Shows Weekly Total Hours, but I need to show weekly OT)

[Figment98]

Hi - I'm pretty new to Power BI, but I'm using it to bring together data from three sources:

• Employee Data (including EE ID, FLSA status, EE status, etc.)
• Payroll Calendar Data (including weeks and pay period parameters)
• Time Data (individual time records from case management system)

I'm trying to build a Matrix Visualization that shows OT per week by employee, like this:

EE ID	Wk 1	Wk 2	Total
AB123	0.02	0.05	1.25
BC234	0	1.01	1.01
CD345	3.08	1.95	9.83

I'm using a Matrix visualization because it looks to function much like a pivot table in Excel, and will allow me to do SUM all of the records for a single employee (ROW) for the week (COLUMN).  The source data doesn't include a total by week, so I need to use Power BI to automate that calculation (which could be anything from 5 unique entries to 50 unique time entries for a week).  

I've gotten to the point where I can get the total by week in the Matrix:

EE ID	Wk 1	Wk 2	Total
AB123	40.02	40.05	80.07
BC234	39.95	41.01	80.96
CD345	43.08	41.95	85.03

But I'm unsure of how to take this result and get it down to the OT for the week.  I can't simply take Total - 80 (40 hours x 2 weeks) because OT is calculated on a weekly basis ONLY on hours over 40.  In the example of EE BC234, the total OT should actually be 1.01, not the 0.96 that would result from Total - 80.  

So I really need to see if EACH WEEK is over 40 before I can total the OT for the period.  The formula needs to operate like this: =IF(VALUE<40,0,(VALUE-40)).

Is there a way to do a calculation like that in a Matrix?  Is there a better way to sum all the time entry records ('Time'[hours_actual]) by employee ('Employee'[Employee ID]) for each week ('Payroll'[Week Start])?

Thanks for any assistance or links to resources that might help.  Appreciate it!  

[DataInsights]

@Figment98,

Try this solution.

Data model:

Measures:

Total Hours = SUM ('Time'[hours_actual] )

Total OT = 
VAR vBaseTable =
    SUMMARIZE ( 'Time', Employee[Employee ID], 'Calendar'[Week End] )
VAR vCalcTable =
    ADDCOLUMNS (
        vBaseTable,
        "@OT",
            VAR vTotalHours = [Total Hours]
            RETURN
                IF ( vTotalHours > 40, vTotalHours - 40 )
    )
VAR vResult =
    SUMX ( vCalcTable, [@OT] )
RETURN
    vResult

In the matrix, use fields from the Calendar and Employee tables, and the measure [Total OT]: