I guess rather I should aski how to not perform KPI calculations when there is no data to perform them on. I can do that to a degree with a calculated measure.

i.e. I can give it non empty behavoir to follow. But there isn't an option for that on the KPI page.

My formulas look like this

Value Expression:

IIF(NOT ISEMPTY([Measures].[Average Loadtime]),[Measures].[Average Loadtime],Null)

Goal Expression:

IIF(NOT ISEMPTY([Measures].[Average Loadtime]),2000,NULL)

Status Expression:

CASE

WHEN (ISEMPTY([Measures].[Count of Instances]))

THEN NULL

WHEN ([Measures].[Average Loadtime]) 2000 and ([Measures].[Average Loadtime]) 5000 then -1

END

Trend Expression:

CASE

WHEN isempty(([Measures].[Average Loadtime])) then NULL when

([Measures].[Average Loadtime]) > (([Measures].[Average Loadtime]),[Time].[Calendar].Prevmember) then 1

WHEN

([Measures].[Average Loadtime]) = (([Measures].[Average Loadtime]),[Time].[Calendar].Prevmember) then 0

WHEN

([Measures].[Average Loadtime]) < (([Measures].[Average Loadtime]),[Time].[Calendar].Prevmember) then -1

END

But it's still leaving all the customers in the list who don't have values to measure the KPI against