Executive summary
2021
ISO 23247 Parts 1–3 (overview, architecture, digital representation) published
2026
Part 6 (digital twin composition) published; it defines how a twin is assembled
Key conclusions
- A digital twin's first job is to let you test the automation decision against a model that behaves like the real line, before you commit the capital.
- ISO 23247 Part 6 defines three composition models (integrated, unified and federated), and the model chosen must match the sites and systems it describes.
- Ask any digital-twin proposal which composition model it uses and why.
If you commit capital to an autonomy project on a line you have only watched running, you are relying on your memory of how it behaves. That includes how it behaves under load, at the start and end of a shift, and on days when something is already slightly wrong. A digital twin is a live, data-fed model of the physical asset, and it removes the need to rely on memory. The standard for digital twins became complete only this year.
ISO 23247 is the international framework for digital twins in manufacturing. Parts 1 to 3 (the overview, the reference architecture and the digital representation) were published in 2021 and set the vocabulary. Part 5, on the digital thread, and Part 6, on digital twin composition, followed in 2026. Part 6 matters most for planning. It defines how twins are assembled, as integrated, unified or federated models, so the software vendor no longer makes that decision by default.
ISO 23247 defines three ways to compose a digital twin
| Model | How it's built | Where it fits |
|---|---|---|
| Integrated | One system holds the model and the data together | A single line or cell, one vendor, no need to federate across systems |
| Unified | A common data model that multiple sources feed into | A plant where several systems already exist and need to agree on one representation |
| Federated | Independent twins linked at defined interfaces, no single shared model | A multi-site operation where sites will not standardise on one platform, and should not have to |
Use the twin first to plan the automation decision
The twin's first job is to let you test the automation decision against a model that behaves like the real line. You can examine failure modes, edge cases and sequencing before you commit capital to the real system.
This works only if the twin's composition model matches the operation it describes. A federated model added to a single line creates integration overhead for no benefit. An integrated model stretched across several sites fails as soon as the sites disagree on a data definition. ISO 23247 Part 6 lets the buyer make this choice deliberately, against a published framework. Without it, the choice often goes to whichever platform vendor reached the buyer first.
To test a digital-twin proposal, ask which of the three ISO 23247 composition models it uses, and why that model suits your operation better than the other two. If the proposal has not considered the question, the twin has not yet been designed.
