The file size is so big. can you place some sample records
Sometimes even if you use ZN function might not get desired result.
Is Sev.2 is an aggregated calculation?
E.g: something like ZN([Profit]/[Sales]) may not give proper result.
Use ZN calculation with aggregation.
Also, try to set default values as null from number properties
Select at Default Value -> Set 0.
Is imposible to me, because i try to apply this function.
Any error are you getting while applying the ZN function. Share screenshots for the same.