[Lauren McGarry]

@Muthu Digital Twin draft standard “BS ISO/IEC 30173 Digital Twin – Concepts and terminology” defines

Simulation: use of a similar or equivalent system to imitate a real system, so that it behaves like or appears to be the real system [SOURCE: ISO 16781:2021, 3.1.9]

Digital Twin (DTw): digital representation of a target entity with data connections that enable convergence between the physical and digital states at an appropriate rate of synchronization. Note 1 to entry: Digital twin have some or all of the capabilities of connection, integration, analysis, simulation, visualization, optimization, etc.

So I would understand that you can have a standalone simulation, e.g. discrete event simulation using a software of choice, but if that software of choice enables convergence to the physical world, then it can be classed as a DTw. For example, Visual Components is a 3D simulation software for manufacturing. You can create a simulation of a manufacturing process. But it also has the capability to connect to PLCs and robots and OPC UA, e.g. Doosan and UR, and with this you can establish convergence with the physical world. 

[Lauren McGarry]

@Melissa Great, thanks. Good to see the comment about the dynamic connection. I think the ISO definition ISO/IEC 30173 covers the basis, and so perhaps it can be accepted that as long it has the ability to connect to the physical asset is a digital twin, but the real purpose and value of a digtial twin is when it is dynamically connected.