Consolidate % using different weighting factor

First things first, I don't think your current measures are working the way you are expecting.

I'm guessing that you could replace your current [Speed units hour] with this measure, and see no difference:

Speed units hour (simple) = SUM(PartesProduccionLineas[Speed/hour])

And that you could replace your current utilization rate with this and get the same results (within a single month. Your ISCROSSFILTERED code helps when multiple months are selected):

Utilization Rate (simple) =
VAR ReferenceTime = 240*8*2 // Total theorical working hours
RETURN
[Opening Time H] / (ReferenceTime/12)

This is just due to you multiplying by extra fields and then immediately dividing by the same value.  You aren't actually weighting either [speed units hour] or [Utilization Rate].

However, it's your Utilization rate that's not giving the correct result, so we want to make a change there.

The best way to get the correct sum of groups that doesn't just use the entire group sum for the calculation is to use a SUMX function with a SUMMARIZE'd table as the input.  

Actual Utilization Rate = 
VAR ReferenceTime = 240*8*2* IF(ISCROSSFILTERED(Calendario[Calendar Month]);DISTINCTCOUNT(Calendario[Calendar Month]);0) // Total theoretical working hours
VAR UtilizationRate = divide([Opening Time H];divide(ReferenceTime;12))
RETURN
DIVIDE( 
    SUMX( SUMMARIZECOLUMNS( PartesProduccionLineas[Line];"Numerator"; [Operating Time H] * [Speed units hour] * UtilizationRate); [Numerator]);
    SUMX( SUMMARIZECOLUMNS( PartesProduccionLineas[Line];"Denominator"; [Operating Time H] * [Speed units hour]); [Denominator])
)

Add this measure in your table in place of [Utilization Rate], and you should get the correct result in your total rows.