ISO/IEC JTC1/SC32/WG2-EM0112-013R2
Date:
2001-12-18
REPLACES: WG2-EM0112-013R1
Source: Ray Gates, based on original proposal from
Frank Farance
In this part of
ISO/IEC 11179, "shall" is to be interpreted as a requirement on an
implementation; conversely, "shall not" is to be interpreted as a
prohibition. If a "shall" or
"shall not" requirement is violated, the behavior is undefined. Undefined behavior is otherwise indicated in
this part of ISO/IEC 11179 by the words "undefined behavior" or by
the omission of any explicit definition of behavior. There is no difference in emphasis among these three; they all
describe "behavior that is undefined".
This part of ISO/IEC
11179 prescribes a conceptual model, not a physical implementation. Therefore, the metamodel need not be
physically implemented exactly as specified. However, it must be possible to
unambiguously map between the implementation and the metamodel in both
directions.
This part of ISO/IEC
11179 also prescribes a list of basic attributes for situation where a full
conceptual model is not required or not appropriate.
Conformance may be
claimed to the either the conceptual model, or the basic attributes or both.
The following
sub-clauses define strictly conforming implementations and conforming
implementations.
The distinction
between "strictly conforming" and "conforming"
implementations is necessary for addressing the simultaneous need for
interoperability and the need for extensions.
Extensions are motivated by needs of users, vendors, institutions, and
industries.
A strictly conforming
implementation:
1) shall support all
mandatory, optional and conditional data element attributes and relationships;
2) shall not use,
test, access, or probe for any extension features nor extensions to data
element attributes;
3) shall not exceed
limits nor smallest permitted maximum values specified by this part of ISO/IEC
11179; and
4) shall not interpret
nor allow the production of data element attributes that are dependent on any
unspecified, undefined, or implementation-defined behavior.
NOTE The use of extensions to the metamodel or the basic attributes may cause undefined behavior.
A conforming
implementation:
1) shall support all
mandatory, optional and conditional data element attributes and relationships;
2) as permitted by the
implementation, may use, test, access, or probe for extension features or
extensions to data element attributes;
3) as permitted by the
implementation, may exceed limits or smallest permitted maximum values
specified by this part of ISO/IEC 11179; and
4) may interpret or
allow the production of data element attributes that are dependent on
implementation-defined behavior.
NOTE 1: All strictly conforming implementations are also conforming implementations.
NOTE 2: The use of extensions to the metamodel or the basic attributes may cause undefined behavior.
Conformance needs to
be considered in the context of the roles and responsibilities of registration
authorities, as covered by ISO/IEC 11179-6: Registration of data elements.
Extended conformance
of systems requires formalisation of procedures, agreement of roles and
responsibilities between parties, and guidelines addressing use of software
products and conversions from other systems. The formalisation of these aspects
must be consistent with the conformance requirements in the above clauses, and
roles of registration authorities as set out in ISO/IEC 11179-6.
The simplification of
clause 6 results in several terms no longer being used.
The following terms
and definitions should be deleted from clause 3:
The following terms
and definitions are used elsewhere in the document, so need to be retained: