Calculating Required Completion Time/Date based on predetermined SLAs

Thanks for the timely response, v-lid-msft! That's almost sorted it, but the hours added needs to be dynamic based on the urgency level. I'm also having some issues with the [date] and [time] fields in your query showing as incorrect syntax. Could it be that i have a calculated field within my extract with these names also?

I've amended your query very slightly to represent the actual field names in my data source as below;

Measure = VAR d = [Date]
VAR t = [Time]
VAR isWorkDay =
    CALCULATE (
        COUNTROWS ( 'Dim_Date' ),
        FILTER (
            'Dim_Date',
            [Date] = d
                && [IsHolidayUK]
                && ( WEEKDAY ( [Date] ) IN { 1, 7 } )
        )
    ) = 0
VAR beforeWorkTime =
    t < TIME ( 9, 0, 0 )
VAR inWorkTime =
    AND ( t >= TIME ( 9, 0, 0 ), t <= TIME ( 17, 0, 0 ) )
RETURN
    SWITCH (
        TRUE (),
        isWorkDay && inWorkTime, d + t + TblKPI.[hours] / 24,
        isWorkDay && BeforeWorkTime, d + TIME ( 9, 0, 0 ) + 4 / 24,
        CALCULATE (
            MIN ( 'Dim_Date'[Date] ),
            FILTER (
                'Dim_Date',
                [Date] > d
                    && NOT ( [IsHolidayUK] )
                    && NOT ( WEEKDAY ( [Date] ) IN { 1, 7 } )
            )
        )
            + TIME ( 9, 0, 0 ) + 4 / 24
    )

i've also included an example extract of how i expect the data to be produced. See below;

Received is the date/time of the received request, straight form the source with no manipulation.

WorkingDayRecieved is calculated based on the Received field, so it defaults to the start of the next working day (9am if raised before 9am, excludes weekends and bank holidays etc)

Required Completion Date when this field is populated with a date/time, this value should be the DueDate of the record. When empty, the due date should be calculated based on the WorkingDayRecieved field plus hours dtermined by the urgency of the request. As you'll see, the first 3 Urgent records have a 4 hour window for completion. The 4th record (ID 73987) is Very High so has been allocated an 8-hour completion window. Meanwhile ID 73873 is low priority so have 40 working hours to complete.

I hope that clarifies any ambiguities, but i'm here to answer anything else that needs clarity. Thanks again for responding so quickly.

A