ISO 18629-11:2005

INTERNATIONAL ISO
STANDARD 18629-11
First edition
2005-10-01

Industrial automation systems and
integration — Process specification
language —
Part 11:
PSL core
Systèmes d'automatisation industrielle et intégration — Langage de
spécification de procédé —
Partie 11: Noyau PSL




Reference number
ISO 18629-11:2005(E)
©
ISO 2005

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ISO 18629-11:2005(E)
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©  ISO 2005
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ISO 18629-11 : 2005 (E)
Contents       Page

1 Scope. 1
2 Normative references . 1
3 Terms, definitions, and abbreviations . 2
3.1 Terms and definitions . 2
3.2 Abbreviations. 7
4 ISO 18629 general . 7
5 Language specification syntax . 8
5.1 Basic symbols and Syntactic Categories. 8
5.2 Lexicon . 9
5.3 Grammar . 9
5.4 Language. 10
6 Basic elements of the PSL Core. 10
6.1 Basic features. 10
6.2 Primitive lexicon of the PSL-Core. 11
6.2.1 Primitive categories of the PSL-Core. 11
6.2.1.1 activity. 11
6.2.1.2 activity_occurrence. 11
6.2.1.3 object . 12
6.2.1.4 timepoint. 12
6.2.2 Individuals of the PSL-Core . 13
6.2.2.1 inf-. 13
6.2.2.2 inf+ . 13
6.2.3 Primitive relations of the PSL-Core . 13
6.2.3.1 before. 13
6.2.3.2 occurrence_of . 13
6.2.3.3 participates_in . 14
6.2.4 Primitive functions of the PSL-Core . 14
6.2.4.1 beginof. 14
6.2.4.2 endof. 14
6.2.5 Theories required by the PSL-Core . 15
6.3 Defined lexicon of the PSL-Core. 15
6.3.1 Formal definitions of the PSL-Core . 15
6.3.1.1 between. 15
6.3.1.2 beforeEq . 15
6.3.1.3 betweenEq . 15
6.3.1.4 exists_at. 16
6.3.1.5 is_occurring_at . 16
6.4 Axioms. 16
6.4.1 Axiom 1 . 16
6.4.2 Axiom 2 . 16
6.4.3 Axiom 3 . 17
6.4.4 Axiom 4 . 17
6.4.5 Axiom 5 . 17
6.4.6 Axiom 6 . 17
6.4.7 Axiom 7 . 17
6.4.8 Axiom 8 . 18
6.4.9 Axiom 9 . 18
6.4.10 Axiom 10 . 18
6.4.11 Axiom 11 . 19
6.4.12 Axiom 12 . 19
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ISO 18629-11 : 2005 (E)

6.4.13 Axiom 13 . 19
6.4.14 Axiom 14 . 19
6.4.15 Axiom 15 . 20
6.4.16 Axiom 16 . 20
6.4.17 Axiom 17 . 20
7 Conformance to PSL-Core. 21
7.1 Conformance of Ontologies. 21
7.2 Conformance of Process Descriptions. 21

Annex A (Normative) ASN.1 Identifier of ISO 18629-11. 22
Annex B (Informative) KIF Syntax and Semantics . 23
Annex C (Informative) Example of process description using PSL-Core . 31
Annex D (informative) BNF Conventions . 40

Figures
Figure C.1 : TOP level process for manufacturing a GT350 [9]. 35
Figure C.2: PROCESS for manufacturing the 350–Engine [9]. 36
Figure C.3: PROCESS for manufacturing the 350–Block [9]. 37
Figure C.4: PROCESS for manufacturing the 350–Harness [9] . 38
Figure C.5: PROCESS for manufacturing the 350–Wire [9] . 38
Figure C.6: PROCESS for manufacturing the x50–Wire. 38

Table
Table C.1: GT-350 Product Structure Table . 33

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ISO 18629-11 : 2005 (E)
Foreword

The International Organisation for Standardisation (ISO) is a worldwide federation of national
standards bodies (ISO member bodies). The work of preparing International Standards is normally
carried out through ISO technical committees. Each member body interested in a subject for which a
technical committee has been established has the right to be represented on that committee.
International organisations, governmental and non-governmental, in liaison with ISO, also take part in
the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all
matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in ISO/IEC Directives, Part 2.
Draft International Standards (DIS) adopted by technical committees are circulated to the member
bodies for voting. Publication as an International Standard requires approval by at least 75% of the
member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this part of ISO 18629 may be the
subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 18629-11 was prepared by Technical Committee ISO/TC 184, Industrial automation systems and
integration, Sub-committee SC4, Industrial data.
A complete list of parts of ISO 18629 is available from the Internet.
http://www.tc184-sc4.org/titles
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ISO 18629-11 : 2005 (E)


Introduction

ISO 18629 is an International Standard for the computer-interpretable exchange of information related
to manufacturing processes. Taken together, all the parts contained in the ISO 18629 Standard provide
a generic language for describing a manufacturing process throughout the entire production process
within the same industrial company or across several industrial sectors or companies, independently
from any particular representation model. The nature of this language makes it suitable for sharing
process information related to manufacturing during all the stages of a production process.
This part provides a description of the core elements of the language defined within the International
Standard.
This part of ISO 18629 and all other parts in ISO 18629 are independent of any specific process
representation or model proposed in a software application in the domain of manufacturing
management. Collectively, they provide a structural framework for improving the interoperability of
these applications.

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INTERNATIONAL STANDARD    ISO 18629-11 : 2005 (E)

Industrial automation systems and integration --
Process specification language --
Part 11:
PSL core

1 Scope
This part of ISO 18629 provides a representation of the concepts of PSL core using a set of axioms
written in the basic language of ISO 18629.
The following is within the scope of this part of ISO 18629:
 the representation of the concepts common to all processes.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
basic only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO/IEC 8824-1, Information technology - Abstract Syntax Notation One (ASN.1) - Specification of
basic notation
ISO 10303-1, Industrial automation systems and integration - Product data representation and
exchange - Part 1: Overview and fundamental principles
ISO 15531-1, Industrial automation systems and integration - Industrial manufacturing management
data - Part 1: General overview
ISO 15531-42:2005, Industrial automation systems and integration - Industrial manufacturing
management data - Part 42:Time model

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ISO 18629-11 : 2005 (E)

3 Terms, definitions, and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
axiom
well-formed formula in a formal language that provides constraints on the interpretation of symbols in
the lexicon of a language
[ISO 18629-1]
3.1.2
conservative definition
definition that specifies necessary and sufficient conditions that a term shall satisfy and that does not
allow new inferences to be drawn from the theory
[ISO 18629-1]
3.1.3
core theory
set of predicates, function symbols and individual constants, associated with some axioms, the
primitive concepts of the ontology
3.1.4
data
a representation of information in a formal manner suitable for communication, interpretation, or
processing by human beings or computers
[ISO 10303-1]
3.1.5
defined lexicon
set of symbols in the non-logical lexicon which denote defined concepts
NOTE Defined lexicon is divided into constant, function and relation symbols.
EXAMPLE  terms with conservative definitions.
[ISO 18629-1]
3.1.6
extension
augmentation of PSL-Core containing additional axioms
NOTE 1  The PSL-Core is a relatively simple set of axioms that is adequate for expressing a wide range of basic
processes. However, more complex processes require expressive resources that exceed those of the PSL-Core.
Rather than clutter the PSL-Core itself with every conceivable concept that might prove useful in describing one
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ISO 18629-11 : 2005 (E)
process or another, a variety of separate, modular extensions need to be developed and added to the PSL-Core as
necessary. In this way a user can tailor the language precisely to suit his or her expressive needs.
NOTE 2  All extensions are core theories or definitional extensions.
[ISO 18629-1]
3.1.7
grammar
specification of how logical symbols and lexical terms can be combined to make well-formed
formulae
[ISO 18629-1]
3.1.8
individual
element of an interpretation domain, in logic, considered as not divisible without loss of identity

EXAMPLE an individual constant is a symbol that is used to refer to some fixed individual object : it is the
equivalent in logic of the "name" in the everyday language. In first-order logic, arguments of predicates are
always individual constants.
NOTE 1  for further information, see [5].
NOTE 2  this term is commonly used in formal logic.
NOTE 3 in first order logic, the only individuals are individual constants.
3.1.9
information
facts, concepts, or instructions
[ISO 10303-1]
3.1.10
interpretation
universe of discourse and assignment of truth values (TRUE or FALSE) to all sentences in a theory

NOTE  See annex C for an example of an interpretation.
3.1.11
language
combination of a lexicon and a grammar
[ISO 18629-1]
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3.1.12
lexicon
set of symbols and terms
NOTE The lexicon consists of logical symbols (such as Boolean connectives and quantifiers) and non-logical
symbols. For ISO 18629, the non logical part of the lexicon consists of expressions (constants, function symbols,
and relation symbols) chosen to represent the basic concepts of the ontology.
[ISO 18629-1]
3.1.13
linear ordering
set of elements with a binary relation between any two elements that is transitive, irreflexive and
antisymmetric

EXAMPLE the less-than relation in mathematics : 3 < 5.
3.1.14
manufacturing
function or act of converting or transforming material from raw material or semi-finished state to a
state of further completion
[ISO 15531-1]
3.1.15
manufacturing process
structured set of activities or operations performed upon material to convert it from the raw material or
a semifinished state to a state of further completion
NOTE Manufacturing processes may be arranged in process layout, product layout, cellular layout or
fixed position layout. Manufacturing processes may be planned to support make-to-stock, make-to-
order, assemble-to-order, etc., based on strategic use and placements of inventories.
[ISO 15531-1]
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ISO 18629-11 : 2005 (E)
3.1.16
model
combination of a set of elements and a truth assignment that satisfies all well-formed formulae in a
theory
NOTE 1 The word "model" is used, in logic, in a way that differs from the way it is used in most scientific and
everyday contexts: if a sentence is true in a certain interpretation, it is possible to say that the interpretation is a
model of the sentence. The kind of semantics presented here is often called model-theoretical semantics.
NOTE 2  A model is typically represented as a set with some additional structure (partial ordering, lattice, or
vector space). The model then defines meanings for the terminology and a notion of truth for sentences of the
language in terms of this model. Given a model, the underlying set of axioms of the mathematical structures used
in the set of axioms then becomes available as a basis for reasoning about the concepts intended by the terms of
the language and their logical relationships, so that the set of models constitutes the formal semantics of the
ontology.
[ISO 18629-1]
3.1.17
ontology
a lexicon of specialised terminology along with some specification of the meaning of terms in the
lexicon
NOTE 1: structured set of related terms given with a specification of the meaning of the terms in a formal
language. The specification of meaning explains why and how the terms are related and conditions how the set
is partitioned and structured.
NOTE 2:  The primary component of a process specification language such as ISO 18629 is an ontology  The
primitive concepts is the ontology according to ISO 18629 are adequate for describing basic manufacturing,
engineering, and business processes.
NOTE 3:  The focus of an ontology is not only on terms, but also on their meaning. An arbitrary set of terms is
included in the ontology, but these terms can only be shared if there is an agreement about their meaning. It is
the intended semantics of the terms that is being shared, not simply the terms.
NOTE 4:  Any term used without an explicit definition is a possible source of ambiguity and confusion. The
challenge for an ontology is that a framework is needed for making explicit the meaning of the terms within it.
For the ISO 18629 ontology, it is necessary to provide a rigorous mathematical characterisation of process
information as well as a precise expression of the basic logical properties of that information in the ISO 18629
language.
[ISO 18629-1]
3.1.18
point in time
location of something noticeable within a time domain
th
EXAMPLE 1 Wednesday, 15 of March, 2003.
EXAMPLE 2 9.30 a.m.
[ISO 15531-42]
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3.1.19
primitive concept
lexical term that has no conservative definition
[ISO 18629-1]
3.1.20
primitive lexicon
set of symbols in the non-logical lexicon which denote primitive concepts
NOTE Primitive lexicon is divided into constant, function and relation symbols.
[ISO 18629-1]
3.1.21
process
structured set of activities involving various enterprise entities, that is designed and organised for a
given purpose
NOTE The definition provided here is very close to that given in ISO 10303-49. Nevertheless ISO 15531 needs
the notion of structured set of activities, without any predefined reference to the time or steps. In addition, from
the point of view of flow management, some empty processes may be needed for a synchronisation purpose
although they are not actually doing anything (ghost task).
[ISO 15531-1]
3.1.22
product
a thing or substance produced by a natural or artificial process
[ISO 10303-1]
3.1.23
proof theory
set of theories and lexical elements necessary for the interpretation of the semantics of the language
NOTE  It consists of three components: the PSL-Core, the Outer Core and the extensions.
[ISO 18629-1]
3.1.24
PSL-Core
set of axioms for the concepts of activity, activity-occurrence, time-point, and object
NOTE  The motivation for PSL-Core is any two process-related applications shall share these axioms in
order to exchange process information, and hence is adequate for describing the fundamental concepts of
manufacturing processes. Consequently, this characterisation of basic processes makes few assumptions about
their nature beyond what is needed for describing those processes, and the PSL-Core is therefore rather weak in
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ISO 18629-11 : 2005 (E)
terms of logical expressiveness. In particular, PSL-Core is not strong enough to provide definitions of the many
auxiliary notions that become necessary to describe all intuitions about manufacturing processes.
[ISO 18629-1]
3.1.25
theory
set of axioms and definitions that pertain to a given concept or set of concepts
NOTE this definition reflects the approach of artificial intelligence in which a theory is the set of assumptions on
which the meaning of the related concept is based.
[ISO 18629-1]
3.1.26
universe of discourse
the collection of concrete or abstract things that belong to an area of the real world, selected according
to its interest for the system to be modelled and for its corresponding environment.
[ISO 15531-1]
3.2 Abbreviations
For the purpose of this part of ISO 18629, the following abbreviations apply:
 BNF Backus-Naur form
 KIF Knowledge Interchange Format
 PSL Process Specification Language
4 ISO 18629 general
ISO 18629 specifies a language for the representation of process information. It is composed of a
lexicon, an ontology, and a grammar for process descriptions.
NOTE 1 PSL is a language for specifying manufacturing processes based on a mathematically well defined
vocabulary and grammar. As such, it is different from the schemas and product representations provided in the
standards ISO 10303, ISO 13584 [2], and ISO 15926 [3], it is also different from the representation provided by
ISO 15531, but strongly related to it and complementary . In the context of an exchange of information between
two software applications, PSL identifies each process independently of its behaviour. For example, an object
identified as a resource within one process can be recognised as the same object even though it is identified as a
product within a second process.
NOTE 2 PSL is based on first order logic; as such, it follows significantly different methods for specifying
semantics for modelling concepts than those used in ISO 10303. The meaning of the concepts defined within
PSL follows from sets of axioms and definitions provided within each extension of PSL-Core. A set of
supporting notes and examples are provided within each part to aid the understanding of the language.
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The parts 1x of ISO 18629 specify foundational theories needed to give precise definitions and the
axiomatization of the primitive concepts of ISO 18629. The foundational theories enable precise
semantic translations between different schemes.
The following are within the scope of the 1x series of parts of ISO 18629:
 the representation of the basic elements of the language;
 the provision of standardised sets of axioms that correspond to intuitive semantic primitive
concepts adequate to describe basic processes;
 the set of rules to develop other foundational theories or extensions in compliance with PSL-Core.
The following is outside the scope of the 1x series of parts of ISO 18629:
 the representation of information involving concepts that are not part of foundational theories.
5 Language specification syntax
This clause specifies the definition of the ISO 18629 language using an extended Backus-Naur form
(BNF) (see Annex D). The syntax described in this section is built on the syntax of the KIF format
provided in the Annex B.
NOTE  for further information, see [7 and [8].
5.1 Basic symbols and Syntactic Categories
The set of basic symbols that shall be used to specify any PSL process description are defined in the
following BNF :
  ::=A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W |
X | Y | Z
  ::= a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z
  ::= |
  ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
  ::= - | ~ | # |$ | * | + | /
  ::= _ | - | ~ | ! | @ | # |$ | % | ^ | & | * | ( | ) | + | = | ` | : | ; | ' | < | > | , | . | ? | / | | |
[ | ] | { | } |
An expression is any string of basic symbols.
There are five basic categories of expression :
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ISO 18629-11 : 2005 (E)
  ::= { | } { | }* {{ _ | - } { | }}*
  ::= ?[']
  ::= { | } { | }* {{ _ | - } { | }}*
  ::= { ...