An operational definition is a procedure agreed upon for translation of a concept into measurement of some kind.
The most important figures that one needs for management are unknown or unknowable.
If you change the rule for counting people, you come up with a new number.
It is wrong to suppose that if you can’t measure it, you can’t manage it – a costly myth.
Data are not taken for museum purposes; they are taken as a basis for doing something. If nothing is to be done with the data, then there is no use in collecting any. The ultimate purpose of taking data is to provide a basis for action or a recommendation for action. The step intermediate between the collection of data and the action is prediction.