ISO 10303-44:2000

Industrial automation systems and integration — Product data representation and exchange — Part 44: Integrated generic resource: Product structure configuration

Systèmes d'automatisation industrielle et intégration — Représentation et échange de données de produits — Partie 44: Ressources génériques intégrées: Configuration de structure de produits

General Information

• Status: Withdrawn
• Publication Date: 20-Sep-2000
• Withdrawal Date: 20-Sep-2000
• ICS: 25.040.40 - Industrial process measurement and control
• Technical Committee: ISO/TC 184/SC 4 - Industrial data
• Drafting Committee: ISO/TC 184/SC 4/WG 12 - STEP product modelling and resources
• Current Stage: 9599 - Withdrawal of International Standard
• Start Date: 02-Dec-2014
• Completion Date: 12-Feb-2026

Relations

• Corrected By: ISO 10303-44:2000/Cor 1:2001 - Industrial automation systems and integration — Product data representation and exchange — Part 44: Integrated generic resource: Product structure configuration — Technical Corrigendum 1
• Effective Date: 06-Jun-2022
• Revises: ISO 10303-44:1994/Cor 1:1999 - Industrial automation systems and integration — Product data representation and exchange — Part 44: Integrated generic resources: Product structure configuration — Technical Corrigendum 1
• Effective Date: 15-Apr-2008
• Revises: ISO 10303-44:1994 - Industrial automation systems and integration — Product data representation and exchange — Part 44: Integrated generic resources: Product structure configuration
• Effective Date: 15-Apr-2008
• Parent: ISO 10303-44:2000/Cor 1:2001 - Industrial automation systems and integration — Product data representation and exchange — Part 44: Integrated generic resource: Product structure configuration — Technical Corrigendum 1
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 10303-44
Second edition
2000-09-01
Corrected
2001-03-15
Industrial automation systems and
integration — Product data representation
and exchange —
Part 44:
Integrated generic resource: Product
structure configuration
Systèmes d'automatisation industrielle et intégration — Représentation
et échange de données de produits —
Partie 44: Ressources génériques intégrées: Configuration de structure
de produits
Reference number
©
ISO 2000
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ii © ISO 2000 – All rights reserved

Contents Page
1 Scope . 1
2 Normative references . 2
3 Terms, definitions, and abbreviations . 3
3.1 Terms defined in ISO 10303-1 . 3
3.2 Terms defined in ISO 10303-41 . 3
3.3 Other terms and definitions . 3
3.4 Abbreviations . 5
4 Product structure . 5
4.1 Introduction . 6
4.2 Fundamental concepts and assumptions . 8
4.3 Product structure entity definitions . 8
4.3.1 alternate_product_relationship . 8
4.3.2 assembly_component_usage . 10
4.3.3 assembly_component_usage_substitute . 11
4.3.4 assembly_component_usage_substitute_with_ranking . 12
4.3.5 make_from_usage_option . 13
4.3.6 make_from_usage_option_group . 14
4.3.7 next_assembly_usage_occurrence . 15
4.3.8 product_definition_occurrence_relationship . 16
4.3.9 product_definition_usage . 17
4.3.10  promissory_usage_occurrence . 18
4.3.11  quantified_assembly_component_usage . 19
4.3.12  specified_higher_usage_occurrence . 19
5 Product concept . 22
5.1 Introduction . 22
5.2 Fundamental concepts and assumptions . 22
5.3 Product concept entity definitions . 23
5.3.1 concept_feature_operator . 23
5.3.2 concept_feature_relationship . 23
5.3.3 concept_feature_relationship_with_condition. 24
5.3.4 conditional_concept_feature . 25
5.3.5 product_concept . 25
5.3.6 product_concept_feature . 26
5.3.7 product_concept_feature_association . 27
5.3.8 product_concept_relationship . 27
6 Configuration management . 28
6.1 Introduction . 29
6.2 Fundamental concepts and assumptions . 30
6.3 Configuration management type definition: configuration_design_item . 30
6.4 Configuration management entity definitions . 30
6.4.1 configurable_item . 30
6. 4. 2 configur a tion_design . . 31
6. 4. 3 configur a tion_effectivity . . 32
6. 4. 4 configur a tion_item . . 33
6. 4. 5 configur a tion_item_rela tionship . . 34
Annex A (norma tive) Shor t names of entities . . 35
Annex B (norma tive) Informa tion object regist r a tion . . 37
B. 1 Document identifica tion . . 37
B. 2 Schema identifica tion . . 37
B. 2. 1 product_st r ucture_schema identifica tion . . 37
B. 2. 2 product_concept_schema identifica tion . . 37
B. 2. 3 configur a tion_management_schema identifica tion . . 37
Annex C (informa tive) Computer -inter pret a ble listing . . 38
Annex D (informa tive) EXP R ES S -G diagr ams . . 39
Annex E (informa tive) Examples . . 43
E. 1 P roduct st r ucture . . 43
E. 1. 1 Example of a mechanical a ssembly product . . 43
E. 1. 2 Examples of product st r ucture repor ts . . 43
E. 1. 3 BOM , pa r t s list , and hybr id da t a st r uctures . . 47
E.1.4 Representation of product structure data structures using ISO 10303-44 entities . 48
E. 1. 5 Gener a ting product st r ucture repor ts . . 56
E. 1. 6 P roduct st r ucture summa ry . . 57
E. 2 P roduct fea tures and product concepts . . 57
Bibliogr a phy . . 61
Index . . 62
Figures
Figure 1 - Rela tionship of schema s within the integr a ted resour ces . . viii
Figure 2 - Relationship of product structure entities to ISO 10303-41 . 7
Figure D. 1 - product_st r ucture_schema . . 40
Figure D. 2 - product_concept_schema . . 41
Figure D. 3 - configur a tion_management_schema . . 42
Figure E. 1 - P a r t 44 example product . . 44
Figure E. 2 - P a r t 44 example product: gr a phical product st r ucture . . 45
Figure E. 3 - BOM da t a st r ucture for pa r t 44 example product . . 48
Figure E. 4 - P a r t s list da t a st r ucture for pa r t 44 example product . . 49
Figure E.5 - BOM data structure examples using ISO 10303-44 entities . 50
Figure E. 6 - BOM da t a st r ucture of pa r t 44 example product . . 51
Figure E.7 - Parts list structure examples using ISO 10303-44 entities . 52
Figure E. 8 - Simple specified higher us age occur rence . . 53
Figure E. 9 - S pecific us ages with specified higher us age occur rence . . 54
iv © ISO 2000 - All rights reserved

Figure E. 10 - Complex specified higher us age occur rence . . 55
Figure E. 11 - Hybr id st r ucture of pa r t 44 example product . . 56
Figure E.12 - Alternate binary operators for conditional_concept_feature . 58
Figure E.13 - Binary operators for conditional_concept_feature . 59
Figure E.14 - Defined operators for conditional_concept_feature . 60
Tables
T a ble 1 - Example 1 make_from_us age_option_group . . 14
T a ble 2 - Example 2 make_from_us age_option_group . . 15
T a ble A. 1 - Shor t names of entities . . 35
Foreword
ISO (the International Organization for Standardization) 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 organizations, 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 the ISO/IEC Directives,
Part 3.
Draft International Standards adopted by the 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 10303 may be the
subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 10303-44 was prepared by Technical Committee ISO/TC 184, Industrial
automation systems and integration, Subcommittee SC 4, Industrial data.
This second edition of ISO 10303-44 constitutes a technical revision of the first edition
(ISO 10303-44:1994), which is provisionally retained to support continued use and maintenance of
implementations based on the first edition, and to satisfy the normative references of other parts of
ISO 10303. This edition incorporates the corrections published in ISO 10303-44:1994/Cor.1:1999.
This International Standard is organized as a series of parts, each published separately. The parts of
ISO 10303 fall into one of the following series: description methods, integrated resources, application
interpreted constructs, application protocols, abstract test suites, implementation methods, and
conformance testing. The series are described in ISO 10303-1.
A complete list of parts of ISO 10303 is available from the Internet:
.
This part of ISO 10303 is a member of the integrated resources series. The integrated resources
specify a single conceptual product data model.
Annexes A and B form a normative part of this part of ISO 10303. Annexes C, D and E are for
information only.
vi © ISO 2000 - All rights reserved

Introduction
ISO 10303 is an International Standard for the computer-interpretable representation and exchange of
product data. The objective is to provide a neutral mechanism capable of describing product data
throughout the life cycle of a product, independent from any particular system. The nature of this
description makes it suitable not only for neutral file exchange, but also as a basis for implementing and
sharing product databases and archiving.
Major subdivisions of this part of ISO 10303 are:
—the product_structure_schema;
—the product_concept_schema;
—the configuration_management_schema.
The product_structure_schema:
— defines a product in terms of its composition as a set of constituents or consumed products. These
products are defined and related at a specific life cycle stage or discipline view. A product may be
assembled from the constituents or produced by consuming other products, or both;
— defines mechanisms for expressing the composition relationship.
The product_concept_schema identifies the product concept as a set of specifications for a product
derived from analysis of customer needs for the product. It represents the idea of a product based on
customer needs and not as it might be designed or built.
The configuration_management_schema identifies those products participating in the configuration of
another product that is under the direct control of an organization.
The relationships of the schemas in this part of ISO 10303 to other schemas that define the integrated
resources of this International Standard are illustrated in Figure 1 using the EXPRESS-G notation.
EXPRESS-G is defined in annex D of ISO 10303-11. The application_context_schema, effectivity_-
schema, and product_definition_schema are specified in ISO 10303-41. The schemas illustrated in
Figure 1 are components of the integrated resources of this International Standard.
Industrial automation is concerned with the management of information including the following:
— product structure;
— product configuration;
— product change.
Product structure is focused on the aspect of product design that defines a product in terms of a nested
decomposition of its constituents. The product structure schema of this part of ISO 10303 and the product
product_concept_schema
application_context_schema
configuration_management _
product_definition_schema
schema
product_structure_schema
effectivity_schema
Figure 1 - Relationship of schemas within the integrated resources
definition schema of ISO 10303-41 together define the representation of the information that manages the
details of product structure. Examples of the use of the information represented are the generation of bill-
of-material reports or the representation of variational bill-of-material structures with conditional part
usages.
Product configuration is concerned with the description of the composition of specific products. The
planning includes specification of the actual constituents of a product that are to be included in a planned
or actual unit. The configuration management schema and the product structure schema represent the
information that manages the configuration of a product. The concept of effectivity is used to manage the
configuration of a product.
Change management is involved with the changes over time in a product as new versions of a product are
developed. This part of ISO 10303 is concerned with changes that affect the organization of constituents
into interrelated structures. The configuration management schema represents information on the structural
form of the definition of a product as the product changes and is enhanced during the product life cycle.
Representation of information on other aspects of change management is defined in the product definition
schema and the action schema of ISO 10303-41.
viii © ISO 2000 - All rights reserved

In this International Standard the same English language words may be used to refer to an object in the real
world or concept, and as the name of an EXPRESS data type that represents this object or concept. The
following typographical convention is used to distinguish between these. If a word or phrase occurs in the
same typeface as narrative text, the referent is the object or concept. If the word or phrase occurs in a bold
typeface, the referent is the EXPRESS data type.
The name of an EXPRESS data type may be used to refer to the data type itself, or to an instance of the
data type. The distinction between these uses is normally clear from the context. If there is a likelihood of
ambiguity, either the phrase "entity data type" or "instance(s) of" is included in the text.
This edition of this part of ISO 10303 incorporates modifications that are upwardly compatible with the
previous edition. Modifications to EXPRESS specifications are upwardly compatible if:
— the modifications do not result in changes to instances that are encoded according to ISO 10303-21;
such instances conform to both the unmodified and modified EXPRESS specifications;
— the modifications do not result in changes to software that conforms to ISO 10303-22 with respect to
access to the data content of data structures;
— the modifications do not invalidate mappings to the previous edition of this part that are specified in
the mapping table of an ISO 10303 application protocol.
Technical modifications to ISO 10303-44:1994 are categorized as follows: changes to the EXPRESS
declarations, new EXPRESS declarations, and changes to definitions.
The following EXPRESS declarations have been modified:
— alternate_product_relationship;
— assembly_component_usage_substitute;
— configuration_design;
— configuration_effectivity;
— configuration_item;
— make_from_usage_option;
— product_concept;
— product_definition_usage;
— quantified_assembly_component_usage;
— specified_higher_usage_occurrence.
The following EXPRESS declarations have been added:
— assembly_component_usage_substitute_with_ranking;
— concept_feature_operator;
— concept_feature_relationship;
— concept_feature_relationship_with_condition;
— conditional_concept_feature;
— configurable_item;
— configuration_design_item;
— configuration_item_relationship;
— product_concept_feature;
— product_concept_feature_association;
— product_concept_relationship;
— product_definition_occurrence_relationship.
The definitions of the following EXPRESS data types have been modified:
— alternate_product_relationship;
— assembly_component_usage;
— assembly_component_usage_substitute;
— configuration_design;
— configuration_effectivity;
— configuration_item;
— make_from_usage_option;
— make_from_usage_option_group;
— next_assembly_usage_occurrence;
— product_concept;
— product_definition_usage;
x © ISO 2000 - All rights reserved

— promissory_usage_occurrence;
— specified_higher_usage_occurrence.
INTERNATIONAL STANDARD ISO 10303-44:2000 (E)
Industrial automation systems and integration —
Product data representation and exchange —
Part 44:
Integrated generic resource: Product structure configuration
1 Scope
This part of ISO 10303 specifies the resource constructs to manage the structure and configuration of a
product during its life cycle.
The following are within the scope of this part of ISO 10303:
— the relationships among the components and assemblies of products;
— the relationships among products and their components as made by modification of other products;
EXAMPLE 1 The machining of a product from another product is an example of a modification.
— the description of a product as defined by customer needs;
— the dependencies among specifications of a product in order to represent possible product variations
to present to a customer;
— the management of the structure for configuration of assemblies and components as planned for
manufacture;
— the decomposition of a product to support different product life cycle activities;
EXAMPLE 2 An organization maintains one bill-of-material structure for a product that enumerates the quantity
of each component used in each assembly, and a second bill-of-material that decomposes a product with multiple
assemblies into the individual components. See annex E for more examples of different product structure reports
that are supported.
— multiple versions of a single product that are equivalent with respect to form, fit, and function.
The following are outside the scope of this part of ISO 10303:
— the relationships among different product definitions for the same product;
NOTE 1 The relationships among different product definitions for the same product are supported by the
product_definition_schema of ISO 10303-41.
EXAMPLE 3 The relationship of a product definition for a component in a preliminary design to a corresponding
product definition for the same component in a detailed design is an example of this type of relationship.
— administrative activities of the product life cycle including approvals, security classifications,
contractual arrangements, and supplier organizations;
— the change process for a product, including the reason for change and what aspect of a product has
changed;
— the decisions made, and their reasons, during the product life cycle;
— the physical connections among components of a product;
— the properties that a product constituent may have;
NOTE 2 A mechanism is defined in the product_property_definition_schema in ISO 10303-41 to support the
association of properties with components. The actual associations are included in various application protocols
that are parts of this International Standard. For example, the details of what a material property is and how it is
defined are out of scope, as well as the fact that a component has a material property.
— multiple versions of a single product that are not form, fit, and function equivalent.
product_definition_schema
NOTE 3 The concept of versions of a product is defined in the in ISO 10303-41.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute
provisions of this part of ISO 10303. For dated references, subsequent amendments to, or revisions of, any
of these publications do not apply. However, parties to agreements based on this part of ISO 10303 are
encouraged to investigate the possibility of applying the most recent editions of the normative documents
indicated below. For undated references, the latest edition of the normative document referred to applies.
Members of ISO and IEC maintain registers of currently valid International Standards.
ISO/IEC 8824-1:1995, Information technology — Abstract Syntax Notation One (ASN.1): Specifi-
cation of basic notation.
ISO 10303-1:1994, Industrial automation systems and integration — Product data representation and
exchange — Part 1: Overview and fundamental principles.
Industrial automation systems and integration — Product data representation and
ISO 10303-11:1994,
exchange — Part 11: Description methods: The EXPRESS language reference manual.
1)
ISO 10303-41:— , Industrial automation systems and integration — Product data representation
and exchange — Part 41: Integrated generic resource: Fundamentals of product description and
support.
1)
To be published.
2 © ISO 2000 - All rights reserved

3 Terms, definitions, and abbreviations
3.1 Terms defined in ISO 10303-1
For the purposes of this part of ISO 10303, the following terms and definitions given in ISO 10303-1
apply.
— assembly;
— component;
— product.
3.2 Terms defined in ISO 10303-41
For the purposes of this part of ISO 10303, the following terms and definitions given in ISO 10303-41
apply.
— agreement of common understanding;
— annotated EXPRESS schema;
— type of product.
3.3 Other terms and definitions
For the purposes of this part of ISO 10303, the following terms and definitions apply:
3.3.1
ancestor node
any node that can be reached from a given node, by successive traversals of links in the reverse direction.
For a given node, its ancestor nodes include all parent nodes, all parent nodes of these parent nodes, etc.
3.3.2
bill-of-material (BOM) data structure
a graph of data elements that depict a bill-of-material structure.
NOTE See annex E for examples of bill-of-material data structures.
3.3.3
bill-of-material (BOM) structure
a description of the structure of a product in terms of its nested constituents.
NOTE See annex E for examples of bill-of-material structures.
3.3.4
child node
the node to which a link is pointing.
3.3.5
configuration item
a subdivision of a product, either a component or an assembly.
3.3.6
descendent node
any node that can be reached from a given node, by successive traversals of links. For a given node, its
descendent nodes include all children nodes, all children nodes of these children nodes, etc.
3.3.7
directed acyclic graph (DAG)
a collection of nodes and links such that no node is an ancestor (or descendant) of itself.
3.3.8
effectivity
a characteristic that indicates whether a product is allowed, approved, or permitted to be used in another
product.
3.3.9
form, fit, and function
a collection of characteristics that include the shape of a product, the way it interfaces with other products,
and the purpose that the product serves.
3.3.10
leaf node
a node that has no children.
3.3.11
link
a uni-directional relationship from one node to another node within a directed acyclic graph.
3.3.12
lot
batch
a collection of distinct products that are treated as a single unit.
EXAMPLE Three thousand bundles of yarn are divided into different groups. Each group is submerged in a
separate barrel of red dye. The group is treated as a lot and assigned a lot number. The lot number is identified
so that conditions causing slight changes in the colour are differentiable among bundles belonging to different lots.
A customer may wish to purchase bundles of the same lot to ensure consistency of the colour.
3.3.13
node
an element of a directed acyclic graph, connected to other such elements by links.
4 © ISO 2000 - All rights reserved

3.3.14
parent node
the node from which a link is initiated.
3.3.15
parts list data structure
a graph of instances that depicts a parts list structure.
NOTE See annex E for examples of parts list data structures.
3.3.16
parts list structure
a description of the structure of a product in terms of a hierarchy of all distinct usages of its constituents.
NOTE See annex E for cases of parts list structures.
3.3.17
promissory use
the intention to use a constituent in an assembly.
3.3.18
root node
a node that has no parents.
3.3.19
tree
a restricted type of directed acyclic graph in which there is only one root node, and in which each node has
at most one parent.
3.4 Abbreviations
For the purposes of this part of ISO 10303, the following abbreviations apply.
BOM bill-of-material
CM configuration management
DAG directed acyclic graph
4 Product structure
The following EXPRESS declaration begins the product_structure_schema and identifies the necessary
external references.
EXPRESS specification:
*)
SCHEMA product_structure_schema;
REFERENCE FROM product_definition_schema
(product,
product_definition,
product_definition_relationship,
acyclic_product_definition_relationship);
REFERENCE FROM measure_schema
(measure_with_unit);
REFERENCE FROM support_resource_schema
(identifier, label, text);
(*
NOTE 1The schemas referenced above are specified in the following part of ISO 10303:
product_definition_schema ISO 10303-41
measure_schema ISO 10303-41
support_resource_schema ISO 10303-41
NOTE 2 See annex D for a graphical presentation of this schema using the EXPRESS-G notation.
NOTE 3 A listing of the complete EXPRESS schema specified in this part of ISO 10303, without comments or
other explanatory text, is available from the Internet - see annex C.
4.1 Introduction
The subject of the product_structure_schema is the relationship between the definitions of:
— products that are assembled to make other products;
— products that are changed to make other products.
These relationships are defined as specializations of a general relationship among product_definitions as
specified in the product_definition_schema in ISO 10303-41. In addition, any product that is used in a
product structure may have alternative products specified for that use. Collectively these relationships are
referred to as a product structure.
The product structure defines the different methods by which a product can be represented as being made
up of constituents. Product structure relationships are established among the constituents that make up a
product. Product structure is an aspect of product definition.
The relationships between product definitions are represented in this part of ISO 10303 using a subtype
of the product_definition_relationship entity as defined in the product_definition_schema in ISO 10303-
41. The subtypes of product_definition_relationship defined in this schema establish additional
constraints and meanings to the supertype in ISO 10303-41.
6 © ISO 2000 - All rights reserved

product_definition
relating_product_definition related_product_definition
name
id
product_definition_relationship
description
product_definition_usage
make_from_usage_option assembly_component_usage
quantified_assembly_
component_usage
specified_higher_ next_assembly_ promissory_
usage_occurrence usage_occurrence usage_occurrence
Figure 2 - Relationship of product structure entities to ISO 10303-41
NOTE Figure 2 shows a partial view of the product_definition_schema in ISO 10303-41 and depicts the subtype
structure of entities defined in this schema. Attributes of the entities defined in this schema and of the product_-
definition entity are not shown. See Figure D.1 for a complete diagram showing all attributes and entities of this
schema.
The product structure concept applies to multiple definitions of the structure of a single product version.
The different definitions correspond to requirements of different organizations for defining the structure
of a product during the life cycle of the product's development.
EXAMPLE An organization may define a bill-of-material structure for both a design engineering release life cycle
activity, as well as for a manufacturing engineering activity.
This schema supports the concept of making a product from another product. This concept deals with the
relationship between a product and the results of a process applied to that product which produces a new
product.
4.2 Fundamental concepts and assumptions
The following concepts and assumptions apply.
— Product structures are modelled by directed acyclic graphs (DAG). In these models, nodes represent
product definitions, and the links represent composed-of relationships. In this schema, nodes
correspond to product_definition entities and the links correspond to assembly_component_usage
entities.
NOTE 1 For a detailed discussion of graph theory, see citation [1] in the bibliography.
— Many forms of product structure can be represented using this schema. Two product structures of
special utility are bill-of-material and parts list structures.
NOTE 2 Examples and diagrams of the manner in which the entities of this part of ISO 10303 may be used to
represent product structures are included in annex E.
— A parts list structure is a specific form of a bill-of-material that can be represented by a tree. Other
bill-of-material structures may require a more general DAG.
— For a general product structure, in order to identify the usage of any constituent within an assembled
product, it is necessary to identify the path between the assembled product and the constituent. The
specified_higher_usage_occurrence entity provides this capability.
4.3 Product structure entity definitions
4.3.1 alternate_product_relationship
The alternate product relationship is an association between two products whereby one product, the
alternate product, may be used in place of another product, the base product.
8 © ISO 2000 - All rights reserved

If one product is an alternate for another product it is understood that there is no interest to keep track of
which product, the base or any alternates specified, is used as a particular instance of the base product
within a product structure.
NOTE An organization may track design changes for a base part, and establish effectivity conditions for the use
of that base part in various assemblies to be manufactured. The use of an alternate product implies that an
organization does not specify any particular version of the alternate product or establish effectivities relating to
it.
An alternate_product_relationship for which the base product is an assembly specifies that the entire
product structure of the alternate product may be used in place of the base product and its product
structure.
EXAMPLE 1 Two bolts of the same size are products. One bolt has a square head and the other has a hexagonal
head. These head shapes are properties of the respective products. The two bolts are considered equivalent with
respect to form, fit, and function: they both have sufficiently close physical shape, they take up the same space
when used, and they both serve to fasten two things together. Thus, one of these two bolts could be considered to
be an alternate part for the other bolt.
The relationship established by the alternate_product_relationship need not be symmetric. If B is an
alternate product for A, A is not implied to be an alternate product for B.
EXPRESS specification:
*)
ENTITY alternate_product_relationship;
name    : label;
definition : OPTIONAL text;
alternate  : product;
base    : product;
basis    : text;
UNIQUE
UR1: alternate, base;
WHERE
WR1: alternate :<>: base;
END_ENTITY;
(*
Attribute definitions:
name: the label by which the alternate_product_relationship is known.
definition: the text that characterizes the alternate_product_relationship. The value of the attribute need
not be specified.
alternate: a product that may be used in place of the base product.
base: a product for which another product may be used as an alternate.
basis: a text description to specify the rationale and criteria used to consider the alternate product in place
of the base product.
EXAMPLE 2 In the alternate_product_relationship for the two bolts defined in example 1, the value of the basis
attribute, could be "head shape", while the value of the definition attribute could be "alternate for use as fastener
in engine assembly".
Formal propositions:
UR1: The combination of the alternate product and the base product shall be unique.
WR1: The instance for the alternate product shall not be the same as the instance of the base product.
4.3.2 assembly_component_usage
The assembly component usage relates a constituent to its assembly. The assembly_component_usage
entity is a subtype of the product_definition_usage entity that should be used to establish a relationship
between product_definitions within one of the following three product structures:
— bill-of-material (BOM) structure;
NOTE 1 In a BOM structure, product_definition entities represent nodes and next_assembly_usage_occurrence
or quantified_assembly_component_usage entities represent links.
— parts list structure;
NOTE 2 In a parts list structure, a product_definition entity represents the root node. The next_assembly_-
usage_occurrence entities represent nodes at each intermediate level of the structure. The specified_higher_-
usage_occurrence entities represent links to higher-levels of the structure.
— promissory use structure.
NOTE 3 In a promissory use structure, product_definition entities represent nodes, and promissory_usage_-
occurrence
entities represent links between the nodes.
NOTE 4 In order to allow for extensions to this entity in other parts of ISO 10303, the SUPERTYPE clause of this
entity is only partially explicit. If the subtypes defined in this part of ISO 10303 were a complete categorization,
the SUPERTYPE clause of this entity could properly read:
SUPERTYPE OF (quantified_assembly_component_usage ANDOR
ONEOF (next_assembly_usage_occurrence,
specified_higher_usage_occurrence,
promissory_usage_occurrence))
EXPRESS specification:
*)
ENTITY assembly_component_usage
SUPERTYPE OF (ONEOF (next_assembly_usage_occurrence,
specified_higher_usage_occurrence,
promissory_usage_occurrence))
SUBTYPE OF (product_definition_usage);
reference_designator : OPTIONAL identifier;
END_ENTITY;
(*
10 © ISO 2000 - All rights reserved

Attribute definitions:
SELF\product_definition_relationship.relating_product_definition: an assembly for which the related_-
product_definition is its constituent.
SELF\product_definition_relationship.related_product_definition: a constituent for which the relating_-
product_definition is its parent assembly.
reference_designator: a distinctive code that serves to identify the usage of the related_product_definition
as a component in the relating_product_definition in a diagram, list, chart, or on a physical piece of
equipment. The value of the attribute need not be specified.
NOTE 5 The reference_designator attribute can be made mandatory, or constrained to be unique, or both, in an
annotated EXPRESS schema that uses or specializes this entity.
4.3.3 assembly_component_usage_substitute
The assembly_component_usage_substitute specifies that one constituent can be used as a substitute for
another within the context of a given assembly.
NOTE 1 The assembly context is specified by the fact that both assembly_component_usages referred to by the
base and substitute attributes reference the same product_definition in their inherited relating_product_definition
attribute.
The instance of the substitute constituent does not require the same spatial relationship or the same
quantity. A substitute constituent does not require equivalent form, fit, and function of the constituent for
which it is a substitute.
This entity defines one-way substitution only. Within a given context, if A is specified as a substitute for
B, B is not implied to be a substitute for A.
NOTE 2 The assembly_component_usage_substitute entity may be used to eliminate the re-identification of all
higher-level assemblies when a new version of a lower-level constituent is created.
EXPRESS specification:
*)
ENTITY assembly_component_usage_substitute;
name       : label;
definition    : OPTIONAL text;
base       : assembly_component_usage;
substitute    : assembly_component_usage;
UNIQUE
UR1: base,substitute;
WHERE
WR1: base.relating_product_definition :=:
substitute.relating_product_definition;
WR2: base :<>: substitute;
END_ENTITY;
(*
Attribute definitions:
name: the label by which the assembly_component_usage_substitute is known.
definition: the text that characterizes the assembly_component_usage_substitute. The value of the
attribute need not be specified.
base: an assembly_component_usage for which the substitute may be used.
substitute: an assembly_component_usage that may be used for the base.
Formal propositions:
UR1: The combination of the base and substitute attributes shall be unique.
WR1: The relating_product_definition attribute of both the base and the substitute attributes shall refer
to the same assembly product_definition.
WR2: The base and substitute attributes shall not be the same instance.
4.3.4 assembly_component_usage_substitute_with_ranking
The assembly_component_usage_substitute_with_ranking is an assembly_component_usage_-
substitute that specifies a relative preference value for the usage of a particular constituent as a substitute
for another among all substitutes within the context of a given assembly.
EXPRESS specification:
*)
ENTITY assembly_component_usage_substitute_with_ranking
SUBTYPE OF (assembly_component_usage_substitute);
ranking      : INTEGER;
ranking_rationale : text;
END_ENTITY;
(*
Attribute definitions:
ranking: an integer that ranks the preference for use of the substitute assembly_component_usage among
all assembly_component_usage_substitute_with_ranking instances with the same value for the base
attribute. This value is an integer that only has meaning when comparing it with corresponding values for
assembly_component_usage_substitute_with_rankings sharing the same base assembly_component_-
usage. It is a relative ranking value, not an absolute ranking. A lower value indicates a higher preference
for the substitute assembly_component_usage, and a higher value indicates a lower preference.
ranking_rationale: text that describes the rationale used for the ranking.
EXAMPLE Examples of ranking_rationale are cost and long lead time.
12 © ISO 2000 - All rights reserved

4.3.5 make_from_usage_option
The make_from_usage_option is a product_definition_usage in which one product is the result of
applying a process to another product.
EXAMPLE 1 Machining, plating, and bending are processes used to make another product.
NOTE 1 In situations in which a product is made from another product using a sequence of processes, the
intermediate products will be related using the make_from_usage_option entity.
NOTE 2 A product to be modified may be an assembly. Generally, the assembly_component_usage differs from
the make_from_usage_option in that the constituents of an assembly are used in the assembly without any change.
NOTE 3 A product_definition may be the relating_product_definition of many make_from_usage_option
relationships, and a product_definition may be the related_product_definition of many make_from_usage_option
relationships. Further, there may be multiple make_from_usage_option instances referencing the same relating_-
product_definition
product_definition and related_product_definition pair of s.
EXAMPLE 2 Consider the case of a shaft that can be machined from either a casting or a forging. All three, the
shaft, the forging, and the casting, are represented by separate instances of product_definition. Two instances of
the make_from_usage_option entity exist, one between the relating_product_definition shaft and the related_-
product_definition forging, the other between the relating_product_definition shaft and the related_product_-
definition casting.
EXPRESS specification:
*)
ENTITY make_from_usage_option
SUBTYPE OF (product_definition_usage);
ranking      : INTEGER;
ranking_rationale : text;
quantity     : measur
...