ISO 21143:2020

INTERNATIONAL ISO
STANDARD 21143
First edition
2020-02
Technical product documentation —
Requirements for digital mock-up
virtual assembly test for mechanical
products
Documentation technique de produits — Exigences sur les essais
d’assemblage virtuel des produits mécaniques
Reference number
©
ISO 2020
© ISO 2020
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ii © ISO 2020 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 VAT process . 3
4.1 General principles . 3
4.2 Workflow process . 3
5 VAT preparation requirements . 4
5.1 General . 4
5.2 Test plan . 4
5.3 Model preparation . 4
5.3.1 Product modelling . 4
5.3.2 Environment modelling . 4
5.3.3 Virtual operator modelling . 5
5.3.4 Model qualification . 5
5.4 Configuration and initialization . 5
6 VAT implementation requirements . 5
6.1 General . 5
6.2 Interference inspection . 6
6.2.1 Inspection tasks . 6
6.2.2 Static interference inspection . 6
6.2.3 Dynamic interference inspection . 8
6.3 Assembly feasibility analysis . 9
6.3.1 Analysis tasks . . 9
6.3.2 Assembly process analysis .10
6.3.3 Ergonomics evaluation .11
7 VAT review requirements .12
7.1 General .12
7.2 Preparation .13
7.3 Plan .13
7.4 Process .13
7.5 Report .13
Annex A (informative) A VAT aeroplane workflow process .15
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
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
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described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 10, Technical product documentation,
Subcommittee SC 6, Mechanical engineering documentation.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv © ISO 2020 – All rights reserved

Introduction
The digital mock-up virtual assembly test (VAT) is a computer simulation procedure in lieu of performing
a physical prototype test for a product to verify the compatibility of the mechanical interface and the
feasibility of assembly. This test can be used to explore and resolve interface and/or assembly problems
before physical product assembly. VAT activities typically include virtual interference inspection,
assembly process analysis and ergonomic evaluation based on 3D nominal models in the design phase.
It can be helpful to consider the results of a VAT to predict and provide early warnings regarding the
risk of interference or assembly problems, although the VAT cannot completely replace all the tests in
on-site assembly testing.
The objectives of the VAT are as follows:
a) verify the mechanical interface compatibility of units, sub-systems and products;
b) ensure that the design output is interference-free and that all contacts or clearances are acceptable;
c) validate layout design at every assembly level;
d) verify assembly feasibility in the manufacturing and operational environments;
e) evaluate the assembly process to optimize the assembly plan.
INTERNATIONAL STANDARD ISO 21143:2020(E)
Technical product documentation — Requirements for
digital mock-up virtual assembly test for mechanical
products
1 Scope
This document specifies the requirements for a digital mock-up virtual assembly test (VAT) for
mechanical products, which is suitable for guiding virtual assembly testing before physical production.
The application of this document is intended to result in an effective VAT and efficient on-site assembly.
This test is applicable to 3D nominal models with theoretically exact dimensions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 17599, Technical product documentation (TPD) — General requirements of digital mock-up for
mechanical products
ISO 29845, Technical product documentation — Document types
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 17599 and ISO 29845 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
design model
portion of the data set that contains models and supplemental geometry
[SOURCE: ISO 29845:2011, 3.1.8]
3.2
3D nominal model
type of design model that contains three-dimensional geometry with theoretically exact dimensions
3.3
virtual assembly test
VAT
test for examining an assembly process in a virtual environment
3.4
simplification
method which allows some features built without modelling or some parts (or components) without
assembling during the modelling process
Note 1 to entry: Through simplification, the geometric detailed representation can be simplified and the model
loading efficiency can be improved provided that the simplification does not incur ambiguous understanding or
bring about inconvenience to the use of a model.
[SOURCE: ISO 17599:2015, 3.12]
3.5
lightweight
method to extract patches from the product geometry model
Note 1 to entry: It reduces resource expenditure in model loading, and it is suitable for large assembly, assembly
simulation, advertising, technical training and so on.
[SOURCE: ISO 17599:2015, 3.13]
3.6
environment model
type of model containing, for example, shop floor or tools and fixtures
3.7
ideal human model
computer-based dummy model in accordance with the actual statistical data set of human body
features, typically as a whole-body model or local feature model, inclusive of citizenship or country of
residence, gender, height and weight, fatigue and other characteristics
3.8
process model
type of model containing an assembly sequence, path and procedure
3.9
assembly process simulation
simulation of an assembly process in a virtual environment for the purposes of planning, analysis and
optimization
3.10
assembly path
movement path of parts or components in an assembly process
3.11
interference
parts of two or more 3D nominal models occupying the same space at the same time
3.12
clearance
two or more adjacent surfaces in the nominal model not touching one another
3.13
contact
two or more surfaces in the nominal model touching one another
2 © ISO 2020 – All rights reserved

4 VAT process
4.1 General principles
A VAT shall be conducted at the design or manufacture start-up phase and shall take into account product
peculiarities and complexity; developer and supplier divisions; software and hardware selection;
basic library development; test and analysis methodologies; legal restrictions; risk management; cost;
schedule; allowable deviations and other constraints. From the unit level through to the integrated
product level, the VAT shall be implemented utilizing appropriate technical methods and suitable test
tasks shall be performed at each assembly level.
4.2 Workflow process
Generally, the VAT process includes the following preparation, implementation and review phases:
a) In the preparation phase, to certify the interface and assembly designs of the product, a VAT plan
shall be developed that includes at minimum the test objectives, test tasks, test methodologies,
test process, test bill of material (BOM) and test schedule. Test models shall be prepared, including
product models, environment models and virtual operator models, and all models shall be certified.
A virtual test environment shall be configured and initialized before moving on to the next phase.
b) In the implementation phase, an interference inspection and assembly feasibility analysis shall
be conducted in a virtual assembly environment. The VAT process and all relevant issues shall be
documented, and the results verified in a closed-loop check.
c) In the review phase, to validate the test results, a review shall be conducted to establish that the
requirements of each of the different phases in the VAT process – preparation, plan, process and
report – have been met.
Figure 1 shows a diagram of the VAT workflow process, and Annex A, Figure A.1, shows a VAT aeroplane
workflow process.
Figure 1 — VAT workflow process
5 VAT preparation requirements
5.1 General
Preparation of a VAT shall comprise the development of a test plan, the preparation of models and
the configuration and initialization of a virtual assembly environment. The test plan, models and
configuration and initialization statuses shall be documented.
5.2 Test plan
The test plan shall include but not be limited to the following:
a) Test objectives: specification of test objectives to verify that the design meets the interface and
assembly requirements when exposed to applicable environments;
b) Test tasks: inspection and analysis tasks developed to meet the test objectives, which shall
be incrementally performed at different assembly levels from the unit level to the integrated
product level;
c) Test methodologies: a suitable combination of inspection and analysis methods, hardware and
software tools and a test process shall be selected or developed to identify latent design defects;
d) Test process: a detailed flow chart of the VAT steps shall be developed to ensure the validity of the
test results;
e) Test BOM: a complete BOM for the VAT shall be provided according to the test tasks, test
methodologies and test process;
f) Test schedule: a time schedule shall be established to ensure the implementation of the VAT in
the appropriate sequence from the unit level to the integrated product level, and the lower-level
assembly testing shall be conducted before initiating upper-level testing.
5.3 Model preparation
5.3.1 Product modelling
A product model shall be developed, which may be simplified and/or lightweighted to improve test
efficiency without affecting the established test objectives, the details of which are as follows:
a) The general modelling requirements for mechanical products shall be followed according to
ISO 17599.
b) The simplified and/or lightweighted models at the unit level for the VAT shall keep their external
geom
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