
140 Part II n The Step-by-Step Guide to the TIQM Quality System
Each Subtype is in fact a ; more specialized classification of members
of the Entity Type. For example, an Employee is a more specialized
kind of Party who must also be a Person.
All Attributes are
;
inherent characteristics of the Type or Subtype with
which they are first associated. Birth date is inherent to Person, not
to the role of a Party as an Employee.
An occurrence of a Subtype inherits ; all Attributes of all its ancestor
super-types. This is a very important rule. The hierarchy is not precise
if there are exceptions to inheritance. It should be noted, however,
that for a given process not all attributes of a super-type are neces-
sarily required for subtype occurrences. For example, Birthdate is an
inherent characteristic of Person. It is a fact required for Customer
and Employee subtypes, but does not need to be known about a
Supplier Contact.
Entity Life-Cycle-State:
■n
The Entity Life Cycle identifies the creation, or existence event, and
;
the deletion, or archiving event.
All Events that may affect or cause significant change to an
;
Occurrence of this Type are identified. Significant change means
that new attributes are known and some different business rules
apply. For example, change of name or address is not a significant
state change event unless new rules apply, such as in insurance
policy coverage.
The ...