Nobody does it "correctly" because they try to use it for a bunch of things that it shouldn't be used for - like performance comparsions. Scrum is only a capac

Nobody does it "correctly" because they try to use it for a bunch of things that it shouldn't be used for - like performance comparsions. Scrum is only a capacity planning tool. Within a certain context, track velocity. When new work comes in, estimate it then compare to velocity. If you don't have the timelines you want, then you need to consider changing scope.