One put into place:

• your objectives, aimed applications, will for digital scalability

• your project, roles and responsibilities (digital contracting authority, digital project manager, synthesis integrator, system coordinators...)

• the principles and constraints on the core systems to install (R2S, IP connectivity, opened and documented APIs)

• your data organization charts (BIM - OT - IT)

Now, it is time to define the framework and the data governance tools:

• the digital twin, the synthesis model of static and dynamic data that structures and makes sense out of the building's data

• the BOS (or DTOS for Digital Twin Operating System). The tool for managing the digital twin and orchestrating the data exchanges within your building's IS

Three key points must be tackled to specify a digital twin:

1. The modelling perimeter. A "digital twin" only has meaning when compared to its "physical twin". What is your digital twin the representative of? A building system, of a building in its entirety, of a campus?

2. The data representation structure. The digital twin must be able to represent the rich, heterogeneous and scalable data. A graph type representation is the only adequate structure to model a building in its entirety (the BIM uses this data structure)

3. The data dynamic. As a synthesis model, the digital twin must be able to integrate static data (BIM, documentation, description...), transaction data (tickets, calendars...) and state and history dynamic data (time series, measure point, alarms, instructions...)

Specify your digital twin

Contrary to the other information system applications that all offer a direct and visible service to the building's users, the BOS is not visible by the users. The BOS is an "infrastructure software" or a "heart system" software or a "middleware". Its principal functions are:

• To integrate and manage the synthesis data model of the building, its digital twin (unique description reference frame, dynamic state, behaviour model).

• To share securely the data from the reference frame between the different applications of the IS

• To orchestrate in a reliable and permanent way the data governance between applications.

Specify your BOS