standardization as new technologies are emerging. However, national and international standardization organizations release new drafts for standards continuously.
The ISO has been developing a series of standards for DTs. The series will include
four different parts, definitions, suitable reference architectures, digital representation of physical manufacturing elements, and information exchange [26–29], and
define the framework of DTs. Another ISO standard under development focuses on
the visualization elements of DTs [30]. These standards are expected to gain
significance for implementing DTs in the future.
Standardization of DTs requires distinction between process and data standards.
Process standards must include definitions of physical objects such as equipment,
machines, or connectors (e.g., pipes). Production types must be defined, and
company-related properties standardized. Here, the International Society of Automation (ISA) and the American National Standards Institute (ANSI) offer suitable
standards for production processes. Notably, the three standard series ISA-88,
ISA-95, and ISA-106 include appropriate methods and tools for DT standardization
[21, 31–46]. The standardization process also supports the analysis of the basic
properties of a production line and its transferability into a DTMS.
With regard to data sets, different levels of the data hierarchy must be defined.
Following the German Electrical and Electronic Manufacturers’ Association
(ZVEI, Zentralverband Elektrotechnik- und Elektronikindustrie e. V.) [47], the
description of data sets emerges from the following aspects:
– Data type (e.g., real, bool, and array) and data format (e.g., XML and JSON)
– Data source (e.g., alarm value and measured value)
– Data semantics (e.g., manual or automatic process)
– Data display (e.g., numerical and curves)
– Aggregated illustration of data (e.g., faceplates and complex diagrams)
– Functional integration of data (e.g., controller and HMI link)
This ontology-driven approach helps the operator to understand the type of data
visible, its origin, and meaning. The DTMS requires a semantic web structure that
helps distinguish between DTs. Management execution systems (MES) can be
combined with DTs, which lead to a full MES-driven approach. The requirements
of management and control of the quality (ISO 9001), the energy (ISO 50001), and
occupational health and safety (ISO 45001) can extend DTMS appropriately and
create a comprehensive production system [48–50].
General management systems, as well as food safety, are feasible in a DTMS.
Here, requirements, limit values, or legislation are applicable to DTs. Food safety
management systems (e.g., ISO 22000), similar concepts and measures, such as
HACCP (hazard analysis and critical control points), are also associated with the
DTMS [51]. These supplements help monitor the hygiene and food safety status in
the production, train employees with customized instructions, and avoid or at least
react promptly in case of a food safety event. Moreover, authorities and audit
organizations are likely to participate in DTMS. The ISO facilitates corresponding
bodies and audits in this field [52]. If a DTMS focuses on tracing and tracking, ISO
suggests principles and basic requirements [53].
The Challenge of Implementing Digital Twins in Operating Value Chains
143
The ISO has been developing a series of standards for DTs. The series will include
four different parts, definitions, suitable reference architectures, digital representation of physical manufacturing elements, and information exchange [26–29], and
define the framework of DTs. Another ISO standard under development focuses on
the visualization elements of DTs [30]. These standards are expected to gain
significance for implementing DTs in the future.
Standardization of DTs requires distinction between process and data standards.
Process standards must include definitions of physical objects such as equipment,
machines, or connectors (e.g., pipes). Production types must be defined, and
company-related properties standardized. Here, the International Society of Automation (ISA) and the American National Standards Institute (ANSI) offer suitable
standards for production processes. Notably, the three standard series ISA-88,
ISA-95, and ISA-106 include appropriate methods and tools for DT standardization
[21, 31–46]. The standardization process also supports the analysis of the basic
properties of a production line and its transferability into a DTMS.
With regard to data sets, different levels of the data hierarchy must be defined.
Following the German Electrical and Electronic Manufacturers’ Association
(ZVEI, Zentralverband Elektrotechnik- und Elektronikindustrie e. V.) [47], the
description of data sets emerges from the following aspects:
– Data type (e.g., real, bool, and array) and data format (e.g., XML and JSON)
– Data source (e.g., alarm value and measured value)
– Data semantics (e.g., manual or automatic process)
– Data display (e.g., numerical and curves)
– Aggregated illustration of data (e.g., faceplates and complex diagrams)
– Functional integration of data (e.g., controller and HMI link)
This ontology-driven approach helps the operator to understand the type of data
visible, its origin, and meaning. The DTMS requires a semantic web structure that
helps distinguish between DTs. Management execution systems (MES) can be
combined with DTs, which lead to a full MES-driven approach. The requirements
of management and control of the quality (ISO 9001), the energy (ISO 50001), and
occupational health and safety (ISO 45001) can extend DTMS appropriately and
create a comprehensive production system [48–50].
General management systems, as well as food safety, are feasible in a DTMS.
Here, requirements, limit values, or legislation are applicable to DTs. Food safety
management systems (e.g., ISO 22000), similar concepts and measures, such as
HACCP (hazard analysis and critical control points), are also associated with the
DTMS [51]. These supplements help monitor the hygiene and food safety status in
the production, train employees with customized instructions, and avoid or at least
react promptly in case of a food safety event. Moreover, authorities and audit
organizations are likely to participate in DTMS. The ISO facilitates corresponding
bodies and audits in this field [52]. If a DTMS focuses on tracing and tracking, ISO
suggests principles and basic requirements [53].
The Challenge of Implementing Digital Twins in Operating Value Chains
143