Does anyone know what FPCKService.cpu in analytics means?

Just another cryptic message that an Apple Engineer decided to log that would only make sense to them. You will find many. Researching analytics looking for a solution to an issue is not something that you will find beneficial.

Anything in Analytics means nothing unless you have special software to read the code and special training know how to apply it.

You won't find that kind of knowledge on a user-to-user site.