Hi Owen, 
Something similar happened to us. We needed to create a report to see requested work in FTEs. 
Our workaround was creating a formula column in the report (field type: numeric).
Maybe that works better for you instead of creating a custom field?

Maca
 

Hi Maca,

Thanks for commenting - I’ve tried to!  In order to get a numeric type from a duration I have to divide a duration by a duration - and I don’t have a useful way of doing this in this context.

What formulae did you use in the report to get numeric type? the days() function doesn’t work in reports and $ActualEffort / 21 gives a Duration type which I can’t caste into numeric as the function to do so doesn’t work in reporting.

Hi Owen,

Sure! This is what we have: 
Catch($CapacityOfUserMonthly.StaffTimePhasedDataForMonthly.LinkObject.RequestedWork/$CapacityOfUserMonthly.WorkingHours,NULL)

Beware: the calculation has a slight variation from what the system shows in the Capacity module in FTEs.

Ah you’re able to access the capacity to be able to divide by a duration to get the numeric.

I need project data in my report so my context ends up being 

user→ labour time phased → project

meaning that I have to divide by the constant rather then the actual working days value.

hence the reason for the custom field - Which doesn’t show up in reporting