ISO 23704-4:2026

• Abstract:

  This document specifies requirements and guidelines for implementing the reference architecture given in ISO 23704-2. Specifically, this document specifies the implementation architecture (IA) including: cyber-physically controlled machine tools (CPCM) for subtractive manufacturing (SM); cyber-supporting system for machine tools (CSSM) for SM. Also, this document provides implementation guidelines (IGs) including: information model of CPSMT for SM; communication model of CPSMT for SM; integration model of CPSMT for SM. As information, the following are included in the annexes: systems engineering (SE) including SE-vee model and stakeholder requirements for SM (see Annex A); use case of IA and IG of CPSMT for SM (see Annex B); an implementation use case for CPSMT (see Annex C).

• Status: Published
• Publication Date: 23-Aug-2026
• ICS: 25.040.20 - Numerically controlled machines
• Technical Committee: ISO/TC 184/SC 1 - Industrial cyber and physical device control
• Drafting Committee: ISO/TC 184/SC 1 - Industrial cyber and physical device control
• Current Stage: 6060 - International Standard published
• Start Date: 24-Aug-2026
• Due Date: 03-May-2026
• Completion Date: 24-Aug-2026

Overview

ISO 23704-4:2026 specifies the general requirements and guidelines for implementing the reference architecture of cyber-physically controlled smart machine tool systems (CPSMT) for subtractive manufacturing. Developed by ISO/TC 184/SC 1, this standard extends the foundational architecture defined in ISO 23704-2, focusing on practical implementation guidance for stakeholders involved in smart manufacturing environments.

This document addresses two primary technical scopes:

• The implementation architecture (IA), including cyber-physically controlled machine tools (CPCM) and the cyber-supporting system for machine tools (CSSM) specific to subtractive manufacturing.
• The implementation guidelines (IGs), which include models and recommendations for information, communication, and integration essential to successful deployment of CPSMT technology for subtractive manufacturing processes.

Key Topics

ISO 23704-4:2026 covers several core topics vital for implementing cyber-physical systems in subtractive manufacturing:

• Implementation Architecture (IA):

  • Defines how to realize the functional architecture described in ISO 23704-2 specifically for smart subtractive machine tools and their supporting systems.
  • Addresses both enterprise-level requirements and physical realization at the shop floor.

• Cyber-Physically Controlled Machine Tools (CPCM):

  • Details on integrating sensors, actuators, and control components to enable real-time and autonomous operations.

• Cyber-Supporting System for Machine Tools (CSSM):

  • Explains systems to support machine monitoring, analytics, and feedback including data processing and system optimization.

• Information Model Guidelines:

  • Recommendations for structuring data, utilizing standardized information models to enhance interoperability.
  • Draws upon international approaches such as OPC UA and associated companion standards.

• Communication Model Guidelines:

  • Guidance on formalized data exchange between CPSMT components, utilizing industry-proven protocols and standards.
  • Applies principles from models such as the OSI reference model.

• Integration Model Guidelines:

  • Proposes methods for combining hardware, software, and service layers to ensure seamless operation across the digital and physical domains.
  • Includes cloud, edge, and fog computing considerations for scalable and flexible system design.

• Systems Engineering and Use Cases:

  • Annexes supply methods like the SE-vee model for project planning and capture typical implementation scenarios on the production floor.

Applications

The standardized approach in ISO 23704-4:2026 brings substantial practical value to the implementation of smart manufacturing with subtractive machine tools:

• For Design Engineers: Provides a framework for integrating smart capabilities in machine tool design, ensuring cyber-physical functionality aligns with international best practices.
• For System Architects: Offers a reference for developing system layouts that support interoperability, scalability, and compliance with Industry 4.0 requirements.
• For Software Engineers and CNC Vendors: Enables consistent development of control and support software, based on agreed-upon information and communication models.
• For Solution and Service Providers: Facilitates the delivery of advanced manufacturing solutions that are compatible with CPSMT environments.
• For Factory Operators and End Users: Promotes clearer communication, better integration of equipment, and enhanced ability to adopt smart manufacturing technologies.

Adopting this standard can lead to:

• Improved interoperability across diverse manufacturing IT and OT systems.
• Enhanced quality and predictability in smart machine tool operations.
• Streamlined development and integration cycles for new and existing manufacturing systems.

Related Standards

To fully leverage the requirements and guidelines outlined in ISO 23704-4:2026, organizations should also reference:

• ISO 23704-1: Overview and fundamental principles for CPSMT.
• ISO 23704-2: Reference architecture for CPSMT in subtractive manufacturing.
• IEC PAS 63088: Reference Architecture Model for Industry 4.0 (RAMI 4.0).
• ISO/IEC 30141: Reference architecture for the Internet of Things (IoT).
• OPC UA (IEC 62541 series): Industrial interoperability protocol.
• ISO 23247: Guidelines for digital twin frameworks in manufacturing.

These standards collectively provide the structural and conceptual underpinnings essential for successful deployment of cyber-physically controlled smart machine tool systems in modern, digitally enabled manufacturing environments.

International
Standard
ISO 23704-4
First edition
General requirements for cyber-
2026-08
physically controlled smart machine
tool systems (CPSMT) —
Part 4:
Requirements and guidelines
for implementing reference
architecture of CPSMT for
subtractive manufacturing
Exigences générales relatives aux systèmes de machines-outils
intelligents à commandes cyber-physiques (CPSMT) —
Partie 4: Exigences et lignes directrices pour la mise en œuvre
de l'architecture de référence des CPSMT pour la fabrication
soustractive
Reference number
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviations . 1
3.1 Terms and definitions .2
3.2 Abbreviated terms .6
4 Conformance with requirements and guidelines for implementation of a CPSMT for
subtractive manufacturing . 7
5 Goals and objectives of the implementation guidelines for subtractive manufacturing . 7
5.1 Goals .7
5.2 Context of this document .7
6 Concept of implementation architecture (IA) and guidelines of CPSMT for subtractive
manufacturing (SM) . 8
6.1 General .8
6.2 Concept of implementation architecture (IA) of CPSMT for subtractive manufacturing
(SM) .9
6.3 Concept of implementation guidelines (IG) of CPSMT for subtractive manufacturing
(SM) .10
7 Implementation architecture (IA) of CPSMT viewed from CPCM .11
7.1 General .11
7.2 Implementation architecture (IA) for CPCM .11
8 Implementation architecture (IA) of CPSMT viewed from CSSM .12
8.1 General . 12
8.2 Implementation architecture (IA) for CSSM . 13
9 Implementation guidelines (IGs) for information model of CPSMT .15
9.1 General . 15
9.2 Information model for CPSMT primary system . 15
9.3 Information model for CNC interface .16
9.4 Information model for MTU state data model in DTU of CSSM .17
9.5 Information model for MTU context data model in DTU of CSSM .18
10 Implementation guideline (IG) of communication model for CPSMT . 19
10.1 General .19
10.2 Communication model for CPSMT . 20
11 Implementation guideline (IG) for Integration model for CPSMT .20
11.1 General . 20
11.2 Reference integration model for CPSMT .21
11.3 Variations and determination of integration model . 22
Annex A (informative) Systems engineering for CPSMT .24
Annex B (informative) Use case for a smart factory platform based on this document .27
Annex C (informative) Use case for a detailed design for implementing architecture of CPSMT .30
Bibliography .34

iii
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.
The procedures used to develop this document and those intended for its further maintenance are 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO’s adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 184, Automation systems and integration,
Subcommittee SC 1, Industrial cyber and physical device control.
A list of all parts in the ISO 23704 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
Since Industry 4.0 and smart factory were announced/proposed by the German government in 2011,
worldwide attention has been focused on this topic. To cope with the megatrend, enabling technologies have
been under development by the industry and R&D institutions.
From the market perspective there is a variety of so called ‘smart machine tools’ incorporating Internet of
Things (IoT), information and communication technology (ICT), smart services. These tools are based on
individual concepts and use local terminologies by machine tool builders (MTBs), as can be seen in the topic
of machine tool control, e.g. computerized numerical control (CNC) vendors, solution vendors, and service
providers, which is confusing for the stakeholders including end-users.
From the standards perspective, RAMI 4.0 (IEC PAS 63088) and IEC TR 63319 provide a reference model
for Industry 4.0 and smart manufacturing on a high level. ISO 23247 series defines a generic framework to
support the creation of a digital twin of observable manufacturing elements. Furthermore, although some
existing standards deal with Industry 4.0 enabling technologies, e.g. OPC-UA (IEC TR 62541-1), MTConnect
[31]
(ANSI/MTC1.4-2018), ISO/IEC 30141, the IEC 62769 series, and many machine tool standards from
ISO/TC 39, no standard yet exists for smart machine tools for realizing smart manufacturing/Industry 4.0
in the shop floor via cyber-physical systems (CPSs). As far as smart machine tool is concerned, the ISO 23704
series has been under development by ISO/TC 184/SC 1/WG 11 since 2018.
The ISO 23704 series specifies general requirements on smart machine tools for supporting smart
manufacturing in the shop floor via cyber-physical system control scheme, namely cyber-physically
controlled smart machine tool systems (CPSMT).
Figure 1 shows the overall structure of the ISO 23704 series, including:
— overview and fundamental principles of a CPSMT in ISO 23704-1;
— reference architecture of a CPSMT for subtractive manufacturing (SM) in ISO 23704-2;
— reference architecture of a CPSMT for additive manufacturing in ISO 23704-3;
— requirements and guidelines for implementing a CPSMT for SM in this document;
— requirements and guidelines for implementing a CPSMT for additive manufacturing in ISO 23704-5.
Other related parts, such as implementation architecture and guidelines or reference architectures for other
types of manufacturing, will be added if and when necessary.
Figure 1 — Overall structure of the ISO 23704 series on general requirements for cyber-physically
controlled smart machine tool systems (CPSMT)
This document and ISO 23704-2 are related in that they both deal with SM but are different aspects of
CPSMTs. ISO 23704-2 defines the functional architecture while this document defines the implementation
architecture and guidelines for a CPSMT for SM given in ISO 23704-2.

v
The objectives of this document are twofold. Firstly, to define requirements for implementations of cyber-
physically controlled smart machine tools (CPSMT) for SM. Secondly, to provide guidelines for implementors
of CPSMT for SM.
Expected impact of this document includes:
a) the promotion of clear and unambiguous communication between all interested parties of smart
machine tools for implementation for Industry 4.0;
b) the promotion of the interoperability of smart machine tools with related hardware devices, software,
service, and manufacturing systems for implementation for Industry 4.0;
c) the promotion of the quality/capability of smart machine tools for Industry 4.0;
d) the promotion of systematic development, modification of smart machine tools for implementation for
Industry 4.0;
e) the promotion of use, e.g. by factory operators, of smart machine tools for Industry 4.0.
This document can be used as a reference and guidelines for stakeholders such as, but not limited to:
— design engineers in the area of the smart SM systems;
— system architects in the area of the smart SM systems;
— software engineers at the SM machine builders in the area of the smart SM systems;
— CNC vendors in the area of the smart SM systems;
— solution and service providers in the area of the smart SM systems;
— end users such as factory operators working with the smart SM systems.

vi
International Standard ISO 23704-4:2026(en)
General requirements for cyber-physically controlled smart
machine tool systems (CPSMT) —
Part 4:
Requirements and guidelines for implementing reference
architecture of CPSMT for subtractive manufacturing
1 Scope
This document specifies requirements and guidelines for implementing the reference architecture given in
ISO 23704-2.
Specifically, this document specifies the implementation architecture (IA) including:
— cyber-physically controlled machine tools (CPCM) for subtractive manufacturing (SM);
— cyber-supporting system for machine tools (CSSM) for SM.
Also, this document provides implementation guidelines (IGs) including:
— information model of CPSMT for SM;
— communication model of CPSMT for SM;
— integration model of CPSMT for SM.
As information, the following are included in the annexes:
— systems engineering (SE) including SE-vee model and stakeholder requirements for SM (see Annex A);
— use case of IA and IG of CPSMT for SM (see Annex B);
— an implementation use case for CPSMT (see Annex C).
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 23704-1, General requirements for cyber-physically controlled smart machine tool systems (CPSMT) —
Part 1: Overview and fundamental principles
ISO 23704-2, General requirements for cyber-physically controlled smart machine tool systems (CPSMT) —
Part 2: Reference architecture of CPSMT for subtractive manufacturing
3 Terms, definitions and abbreviations
For the purposes of this document, the terms and definitions given in ISO 23704-1 and ISO 23704-2 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 Terms and definitions
3.1.1
asset administration shell
AAS
virtual digital and active representation of an Industry 4.0 component in the Industry 4.0 system
Note 1 to entry: Administration shell (AS) is defined in ISO 23704-1, but AAS is also used in the Industry 4.0 paradigm.
Note 2 to entry: The AAS defines the accessible functionality of an asset. An asset will often have other functionality
to support the accessible functionality which should only be used in the context of the accessible functions and should
not be invoked separately.
1)
[SOURCE: IEC PAS 63088:2017 , 3.1, modified — The term was changed from “administration shell” to
“asset administration shell”; Note 1 to entry was changed and Note 2 to entry was added.]
3.1.2
big data
BD
technologies addressing data sets that are so large and complicated that traditional data-processing
application software are inadequate for management and utilization of the data
Note 1 to entry: Big data is dealt with by CSSM in a systematic way via DPU (data processing unit), in particular.
Note 2 to entry: Adapted from IEC TR 63319:2025, 4.3.4.
3.1.3
cloud computing
technology that enables ubiquitous access to distributed and shared pools of system resources and services
with minimal management effort
Note 1 to entry: Cloud computing together with edge computing (3.1.8) and fog computing (3.1.9) is reflected in the
Integration model of cyber-physically controlled smart machine tool (CPSMT) in Clause 11.
Note 2 to entry: Adapted from IEC TR 63319:2025, 4.3.4.
3.1.4
communication model
formalized conceptual representation of the process of communication
Note 1 to entry: See Clause 10 for more on communication models for the cyber-physically controlled smart machine
tool (CPSMT).
3.1.5
communication protocol
formalization of communication between two functional elements including syntax, meaning and other
information relevant to the type of communication
Note 1 to entry: Different protocols are relevant for different tasks and examples of relevant protocols are given where
appropriate.
1) Withdrawn.
3.1.6
concern
subject that is the result of a perspective (3.1.18) or use case
Note 1 to entry: Adapted from IEC TR 63319:2025, 6.4.2.5.
3.1.7
digitalization
use of digital technologies to move a business model to a digital system and provide new revenue and value-
producing opportunities
Note 1 to entry: Digitalization of physical asset can be done via asset administration shell (AAS) (3.1.1), etc.
Note 2 to entry: See [49] for a comparison of digitalization and digital transformation with digitization.
3.1.8
edge computing
methods for optimizing computing systems by placing control in applications/services with direct contact
with the physical world, rather than in central nodes
Note 1 to entry: Edge computing together with fog computing (3.1.9) and cloud computing (3.1.3) is reflected in the
Integration model of cyber-physically controlled smart machine tool (CPSMT) in Clause 11.
Note 2 to entry: Adapted from IEC TR 63319:2025, 4.3.4.
3.1.9
fog computing
computer architecture using edge computing (3.1.8) for computation, storage and communication
Note 1 to entry: Fog computing together with edge computing and cloud computing (3.1.3) is reflected in the Integration
model of cyber-physically controlled smart machine tool (CPSMT) in Clause 11.
3.1.10
functional architecture
FA
arrangement of functions and their subfunctions and interfaces (internal and external) that defines the
execution sequencing, conditions for control or data flow, and the performance requirements (3.1.21) to
satisfy the requirements baseline
[SOURCE: ISO/IEC/IEEE 24765:2017, 3.1687.1]
3.1.11
human-machine interface
HMI
design and implementation of systems interacting with humans
Note 1 to entry: The HMI for the cyber-physically controlled smart machine tool (CPSMT) is necessary but an exact
definition is out of scope for this document.
Note 2 to entry: HMI is dealt with in the use case described in ISO 23704-2:2022, Clause C.2.
3.1.12
input, consideration/constraints, output, method/mechanism
ICOM
method used for defining context or requirements (3.1.21) of system of interest (SoI) in systems engineering
Note 1 to entry: ICOM is an advanced methodology for developing complex systems based on Icam DEFinition for
Function Modeling (IDEF0).
Note 2 to entry: For details on systems engineering, see ISO/IEC/IEEE 15288, ISO/IEC/IEEE 12207,ISO/IEC/IEEE 42010.

Note 3 to entry: IDEF0 may be used to model a wide variety of automated and non-automated systems. For new systems,
it may be used first to define the requirements and specify the functions, and then to design an implementation that
meets the requirements and performs the functions. For existing systems, IDEF0 can be used to analyze the functions
[35]
the system performs and to record the mechanisms (means) by which these are done .
Note 4 to entry: In this document, the ICOM method is performed to identify input, consideration/control, output,
and method for every functional element specified in ISO 23704-2, for the sake of developing the implementation
architecture (3.1.13), information model (3.1.15), computing model, and integration model for cyber-physically
controlled smart machine tool (CPSMT).
3.1.13
implementation architecture
IA
arrangement of functional architecture (3.1.10) for implementation of a cyber-physically controlled smart
machine tool (CPSMT)
Note 1 to entry: The implementation architecture includes functional flow based on ICOM (3.1.12) analysis of
functional elements specified in ISO 23704-2 including input, output to group of related elements.
3.1.14
implementation guideline
IG
recommendation of recognized practice to be considered for translating a design/specification into either
hardware components or software components, or both
Note 1 to entry: In this document, implementation guidelines take into consideration market practice, industry
standards, cyber-physically controlled smart machine tool (CPSMT) principles, etc., so that the system considered can
become operational.
Note 2 to entry: According to layer-axis between functional layer and physical layer of RAMI4.0, implementation
guideline for CPSMT includes information model (3.1.15), communication model (3.1.4), and integration model, etc.
3.1.15
information model
representation of concepts and the relationships, constraints, rules and operations to specify data
semantics for a chosen domain of discourse
Note 1 to entry: In software engineering this typically specifies relations between kinds of things, but may also include
relations with individual things. It can provide sharable, stable and organized structure of information requirements
[38]
(3.1.21) or knowledge for the domain context .
Note 2 to entry: In this document, information model specified by OPC UA (see IEC 62541-5) and its companion
[30]
standard, OPC 40502-1 is referenced and represented by the notion of UML (see ISO/IEC 19501) as an information
model for cyber-physically controlled smart machine tool (CPSMT).
3.1.16
open platform communications unified architecture
OPC UA
cross-platform, open-source, standard for data exchange from sensors to cloud applications developed by
the OPC Foundation
3.1.17
open platform communications unified architecture computerized numerical control interface
OPC UA CNC interface
specification for information model (3.1.15) for computerized numerical control (CNC) systems
Note 1 to entry: The CNC interface is a companion to OPC UA (3.1.16) according to OPC UA published by OPC foundation
[30]
and VDW, as OPC 40502-1 .
3.1.18
perspective
orientation of a stakeholder (3.1.23) within a smart manufacturing domain
Note 1 to entry: Stakeholder has its own perspective arising from their knowledge, expertise, responsibility, authority
and accountability relative to a smart manufacturing effort.
Note 2 to entry: Adapted from IEC TR 63319:2025, 6.4.2.3.
3.1.19
predictive maintenance
process that uses sensing and analysis of measured data for systematic detection of trends and prediction of
incipient failures to prevent faults from occurring
3.1.20
prototype
PT
preliminary type, form, or instance of a system that serves as a model for later stages or for the final,
complete version of the system
Note 1 to entry: A prototype is a method of obtaining early feedback on requirements (3.1.21) by providing a working
model of the expected product before actually building it.
3.1.21
requirement
desired feature, property, or behavior of an element as part of a system
3.1.22
smart machine
autonomously operating, communicating, adaptive and possibly learning system able to solve problems and
make decisions independently of people
Note 1 to entry: The cyber-physically controlled smart machine tool (CPSMT) of the ISO 23704 series is smart machine
tool systems for Industry 4.0.
3.1.23
stakeholder
individual, organization, or classes thereof, having an interest in a system
Note 1 to entry: See Annex A for the stakeholders of cyber-physically controlled smart machine tool (CPSMT).
[SOURCE: ISO/IEC/IEEE 42010:2022, 3.17, modified — “role” and “position” were removed from the start
of the definition; “an interest right, share, or claim, in an entity of interest” was changed to “an interest in a
system”; the Example was removed and Note 1 to entry was added.]
3.1.24
transmission control protocol/internet protocol
TCP/IP
framework for organizing the set of communication protocol (3.1.5) commonly known as Internet protocol
suite, used in the Internet and similar computer networking according to functional criteria

3.2 Abbreviated terms
AAS asset administration shell
AI artificial intelligence
BD big data
CAx computer-aided-x
CNC computerized numerical control
CPCM cyber-physically controlled machine tool
CPSMT cyber-physically controlled smart machine tool
CSSM cyber supporting system for machine tool
DPU data processing unit
DTU digital twin unit
FA functional architecture
HMI human machine interface
IA implementation architecture
ICOM inputs, controls, outputs, and mechanisms
IG implementation guideline
MAPE monitoring, analysis, planning, execution
MTU machine tool unit
NCK numerical control kernel
OPC UA open platform communication unified architecture
OSI open system interconnection
PI physical implementation
PLC programmable logic controller
PT prototype
SE systems engineering
SFCS shop floor control system
SFDS shop floor device system
SM subtractive manufacturing
TCP/IP transmission control protocol internet protocol
UIS unified interface system
4 Conformance with requirements and guidelines for implementation of a CPSMT
for subtractive manufacturing
This document is based on the reference architecture defined in ISO 23704-1 and ISO 23704-2.
To claim conformance, definition of a specific system architecture shall use the terminology, architectural
concepts and have the capabilities defined in ISO 23704-1 and ISO 23704-2. It shall also follow the information
requirements defined in this document, within the scope of their specific use cases.
5 Goals and objectives of the implementation guidelines for subtractive
manufacturing
5.1 Goals
ISO 23704-2 has been developed for subtractive manufacturing (SM) based on the generic architecture
given in ISO 23704-1. Viewed from the level of architecture, ISO 23704-2 is a functional level as described in
the scope of both ISO 23704-1 and ISO 23704-2, how to implement a CPSMT is a key issue, which has been
raised by stakeholders such as CNC vendors, MTBs, etc. In other words, it is necessary to provide some sort
of guidelines for implementing the reference architecture of CPSMT for the sake of physical realization of
CPSMT in industry.
NOTE Figure 2 illustrates the goals and objectives of this document. The left hand part of the figure is simplified
from ISO 23704-2:2022, Figure 3 while the right hand side is Figure 14 in this document. The figure is illustrative only
of the implementation process. For details of these elements, see the original figures.
Figure 2 — Goals and objectives of implementation guidelines of CPSMT for subtractive
manufacturing (SM)
5.2 Context of this document
Figure 3 illustrates the context of how the CPSMT implementation architecture and guideline for SM is
derived from the various perspectives based on the architecture description defined in ISO/IEC/IEEE 42010.
The boxes with a thicker, grey outline in the figure are elements of this document, the black boxes are
external elements. The grey arrows represent connections between clauses and annexes in this document
while the black arrows are connections from outside.

NOTE The direction of the arrows indicates source and reflection of the entities.
Figure 3 — Context of the CPSMT requirements and guidelines for subtractive manufacturing (SM)
Based on Figure 3, this document includes the following descriptions:
— concept of implementation architecture (IA) and implementation guideline (IG) for SM in Clause 6;
— IA viewed from CPCM perspective for SM in Clause 7;
— IA viewed from CSSM for SM in Clause 8;
— IG viewed from information model for CPSMT in Clause 9;
— IG viewed from communication model for CPSMT in Clause 10;
— IG viewed from integration model for CPSMT in Clause 11;
— informative information, including stakeholders’ requirements, use cases, etc. in the annexes.
6 Concept of implementation architecture (IA) and guidelines of CPSMT for
subtractive manufacturing (SM)
6.1 General
This clause describes implementation view of CPSMT for SM including:
— IA (displayed in the bottom-left of Figure 4) viewed from implementation of functional architecture (FA)
of CPSMT (displayed in the top);

— IG (displayed in the bottom-center of Figure 4) of CPSMT for physical implementation (PI) of CPSMT for
SM (displayed in the bottom-right).
NOTE Figure 4 shows the relation of the different elements. The FA at the top is ISO 23704-2:2022, Figure 3. The
IA on the left is Figure 7 in this document. The PI is Figure 14 in this document. The IG in the centre at the bottom are
described in Clause 9. For details, refer to the original figures and the relevant clause.
Key
1 functional architecture (FA) (simplified ISO 23704-2:2022, Figure 3)
2 IA (Figure 7 in this document)
3 IG (described in Clause 9. These provide guidelines for physical implementation model of CPSMT; Integration
model of CPSMT; Digitization model of CPSMT; Use cases, etc.)
4 physical implementation (PI) (Figure 14 in this document)
Figure 4 — Concept of implementation architecture (IA) and implementation guidelines (IG) of
CPSMT for subtractive manufacturing (SM)
6.2 Concept of implementation architecture (IA) of CPSMT for subtractive manufacturing
(SM)
The implementation concept given in this clause is derived based on:
— the reference architecture including ISO 23704-1 and ISO 23704-2 (respectively left and right in Figure 5);
— top down architecture (top in Figure 5), from smart manufacturing including RAMI 4.0 (see
IEC/PAS 63088), SMRM (see IEC TR 63319), Digital Twin (see ISO 23247), Smart Factory (see Reference
[39]), etc.;
— bottom up architecture (bottom in Figure 5) from:
— market products including hardware, software, serviceware in major international machine tool
shows;
— R&D on state-of-the-art of enabling technology related with smart machine tool system for Industry
4.0.
The details of the IA for CPCM and CSSM of the CPSMT primary system for SM are given in Clauses 7 and 8,
respectively.
NOTE Figure 5 shows the relationship between different elements. For details of the elements, please refer to the
documents referenced in 6.2.
Figure 5 — Concept of implementation architecture (IA) for subtractive manufacturing (SM)
6.3 Concept of implementation guidelines (IG) of CPSMT for subtractive manufacturing
(SM)
IGs supporting the IA can be derived based on RAMI 4.0 (Reference Architecture Model for Industry 4.0)
given in IEC/PAS 63088.
th
In terms of the layer axis of RAMI 4.0, ISO 23704-1 and ISO 23704-2 are at the 5 layer, while physical
layer at the first layer as illustrated in Figure 6. IG, in essence, is to provide technologies between the two
layers, i.e. information, communication and integration, as illustrated in Figure 4, which is tailored for the
implementation of CPSMT for SM (the scope of this document).
NOTE The left part of Figure 6 shows the RAMI 4.0 architecture. See ISO 23704-1, Figure A.3 for the full-sized
figure. The top layer concerns business and is not within the scope of this document. The second layer concerns the
functional characteristics, which are also outside the scope of this document, and which are dealt with in ISO 23704-1
and ISO 23704-2. The next three layers are the subject of the implementation guidelines. These are:
— information;
— communication;
— integration and digitalization, key elements of AAS.
The details of implementation guidelines for information model, communication model and integration
model for CPSMT for SM are given in Clauses 9, 10 and 11, respectively.

Figure 6 — Concept of implementation guideline (IG) for subtractive manufacturing (SM)
7 Implementation architecture (IA) of CPSMT viewed from CPCM
7.1 General
In this clause, IA viewed from CPCM is described based on the concept of IA given in 6.2.
7.2 Implementation architecture (IA) for CPCM
IA for CPCM given in Figure 7 is, in essence, functional flow of each element specified in ISO 23704-2:2022,
Figure 3. Contents of functional flow include data/signal between elements, derived based on ICOM analysis.
IA for CPCM in Figure 7 consists of three components:
a) CNC including NCK, NCK-PLC interface, and PLC;
b) MTU excluding CNC from the 6 elements in that of FA (given in ISO 23704-2:2022, Figure 3);
c) CPS unit including inner-loop, intra-loop, and inter-loop elements of FA (given in ISO 23704-2).
NOTE 1 In Figure 7, compared with FA (ISO 23704-2:2022, Figure 3), CPS unit, distinguished feature from
conventional CNC system is highlighted, while MTU is simplified into CNC and MTU excluding CNC.
NOTE 2 In Figure 7, the dashed arrows concern communication outside the CPSMT. While it is necessary to show
these connections, they are not within the scope of this document and so they are not detailed further.

Key
1 data exchange between a CPCM and UIS
2 data/control from CNC to MTU/inner-loop/intra-loop/inter-loop elements
3 data/control signal from sensor to CSSM/inner-loop/intra-loop/inter-loop elements
4 data/signal from inner-loop element to CNC
5 data from CSSM to intra-loop element
6 data/signal from intra-loop to CNC
7 data from SFCS to inter-loop element
8 data/signal from inter-loop to CNC
9 data/signal between CPCM and SFDS
10 data between CSSM and SFCS
11 data between UIS and CSSM
12 data between UIS and SFCS
13 data between SFCS and SFDS
14 interface between human and UIS
15 data between life cycle aspect and UIS
16 data between UIS and hierarchical levels
17 data between SFCS and hierarchical levels
18 data between UIS and SFDS
Figure 7 — Implementation architecture (IA) viewed from CPCM for subtractive manufacturing
(SM)
8 Implementation architecture (IA) of CPSMT viewed from CSSM
8.1 General
In this clause, IA viewed from CSSM is described based on the concept of IA given in 6.3.

8.2 Implementation architecture (IA) for CSSM
IA for CSSM given in Figure 8 includes functional flow, relationship and characteristic of each element
specified in ISO 23704-2:2022, Figure 3. Contents of these are derived based on ICOM analysis.
IA for CSSM in Figure 8 specifies elements in 4 units:
a) DPU including:
1) UIS interface;
2) CPCM interface;
3) data fusion;
4) data storage;
5) data transformation;
b) DTU including:
1) MTU state information model;
2) MTU context information model;
3) MTU state management;
4) behavior model;
5) behavior model engine;
c) MAPE unit including:
1) monitoring;
2) analysis;
3) planning;
4) execution;
d) EIU including:
1) interface schema;
2) interface management.
NOTE 1 In Figure 8 (as in Figure 7) the dashed arrows concern communication outside the CPSMT. While it is
necessary to show these connections, they are not within the scope of this document and so they are not detailed
further.
NOTE 2 The MAPE operation uses big data (BD) analytics to support CSSM operation.
NOTE 3 The MAPE unit is also responsible for predictive maintenance as a solution for developing anomalies.

Key
1 data exchange between a UIS and CSSM
2 information model specified by interface schema of EIU, e.g. OPC UA
3 data/control signal sent to CPCM interface element from CNC and sensor
4 data sent to Data fusion element from UIS interface element
5 data sent to Data fusion element from CPCM interface element
6 MTU state information model specified to Data fusion element
7 MTU context information model specified to Data fusion element
8 data sent to Data storage element from Data fusion element
9 data sent to Data transformation element from Data fusion element
10 data sent to Interface management from Data transformation element
11 data sent to MTU state management element from Data fusion element
12 data sent to Behavior model engine from MTU state management element
13 behavior model provided to Behavior model engine from Behavior model element
14 data sent to Data storage element from MTU state management
15 data exchange (sent/received) between Data storage element and Behavior model engine
16 data exchange (sent/received) between Data storage element and MAPE unit
17 data sent to MAPE unit from Behavior model engine
18 data sent to CPCM from execution element of MAPE unit
19 data sent to Interface management element from the MAPE unit
20 data sent to Interface management element from Data storage element
21 data sent to SFCS from Interface management element
22 data exchange (sent/received) between UIS and CPCM
23 data exchange (sent/received) between UIS and SFCS
24 data exchange (sent/received) between UIS and Human
25 data exchange (sent/received) between UIS and Life cycle aspect
26 data exchange (sent/received) between UIS and Hierarchy levels
27 data exchange (sent/received) between SFCS and SFDS
Figure 8 — Implementation architecture (IA) viewed from CSSM for subtractive manufacturing (SM)

9 Implementation guidelines (IGs) for information model of CPSMT
9.1 General
Based on the concept IGs of CPSMT in 6.3, this clause describes the information model for CPSMT based on
OPC UA (see IEC 62541-5), which has been emerging as an information model for interoperability of smart
manufacturing. Under the basic model of OPC UA, a domain specific model has been under development as
a companion standard. In this clause, a companion standard released by OPC UA foundation and VDW has
been referenced and represented by the notion of UML (see ISO/IEC 19501) as an information model for
CPSMT.
Considering that CPSMT is system of systems capable of autonomously dealing with abnormalities via CPS
and CSSM, coordination with SFDS, collaborating with SFCS, and external entities (Human, Lifecycle aspect,
and Hierarchical levels, objects, types, variables, etc.) are more comprehensive compared with that of OPC
[30]
UA CNC interface model .
In this clause, based on IA for CPCM and CSSM, respectively given in Clauses 7 and 8, an information model
for a CPSMT Primary System (‘CPSMTPrimarySystemType’ in Figure 9) consists of CPCM and CSSM as its
subtypes, and elements of IA for CPCM and IA for CSSM.
In Figures 10, 11 and 12, respectively data models for ‘CNCInterfaceType’ in ‘CPCMType’, ‘MTUStatedataModel’,
and ‘MTUContextdataModel’ in ‘DTUType’ in ‘CSSMType’ are given, respectively.
NOTE The information model of the elements can be used as a basis for implementation of the internal software
structures. They also form a basis for the internal information flow and for the necessary functionality of the software.
9.2 Information model for CPSMT primary system
An information model for the CPSMT primary system is shown in Figure 9. The primary system concerns
the CPCM and CSSM and the information model provides a formal description of these. The model can be
used to provide common information for the control software.
Based on the information in Figure 7, the CPCM type has two sub-elements: the MTU type and the CPS Unit
type.
The MTU Unit concerns the Process Conditioning Type, the Workpiece Handling Type, the Tool Handling
Type, the Waste Handling Type, the Cooling/Heating Type and the Machine Tool Operation Type. The Machine
Tool Operation Type concerns the Machining Process, the Machining Motion and the Machining Control. The
Machining Control concerns the CNC Interface Type (NCK Type, PLC Type and NCK-PLC Interface Type). The
Fieldbus Interface Type, the I/O Modules Type and the Sensor/Actuator Type.
The CPS-Unit has the three elements: Inner loop Element Type, Intra loop Element Type and Inter
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