Super-type/sub-type relationships may be exclusive or not. A methodology may require that each instance of a super-type may only be an instance of one sub-type. Similarly, a super-type/sub-type relationship may be exhaustive or not. It is exhaustive if the methodology requires that each instance of a super-type must be an instance of a sub-type. A sub-type named "Other" is often necessary.
Super-type/sub-type relationships may be exclusive or not A methodology may require that each instance of a super-type may only be an instance of one sub-type Similarly a super-type/sub-type relationship may be exhaustive or not It is exhaustive if the methodology requires that each instance of a super-type must be an instance of a sub-type A sub-type named "Other" is often necessary