Virtual construction model

Building Information Modelling (BIM) is a very broad term that describes the process of creating and managing digital information about a building or other facility such as a bridge, highway, tunnel, and so on. Fundamentally, the purpose of BIM is to ensure that appropriate information is created in a suitable format at the right time so that better decisions can be made throughout the design, construction and operation of built assets.

In the early stages of a project, the building information model (sometimes referred to as a project information model (PIM)) might simply include existing information such as site surveys, condition surveys, information about existing utilities, and so on. This information might be generated from an existing asset information model (AIM) used to operate and maintain a built asset.

During the design stages of a project, a design intent model is developed. This becomes more detailed as the project progresses, and ultimately, as contractors take over development of the model from designers, it may become a virtual construction model (VCM), containing information allowing all objects in the model to be manufactured, installed or constructed.

The virtual construction model provides information describing the detailed design, and may also include:

A detailed construction sequence that might be linked to a project management scheduling tool.
Information about temporary works such as fences, scaffolding, facade retention structures, falsework, formwork and so on.
Method statements.
Safety briefing information, security status information and visualisations of potentially hazardous activities.
Access details, traffic routes and diversions.
Crane zones and other lifting operations.
Information about site logistics.

The virtual construction model may be used for activities such as:

Visualising and planning the construction sequencing and site logistics.
Clash avoidance and clash detection, including soft clashes, such as too little space to install or maintain a component of the building, the installation of insulation, proximity clashes and so on.
Manufacturing processes.
Providing access to information on site, increasingly using mobile devices and tablets.
Health and safety risk management, site inductions and safety briefing.
Security tracking.
Improving familiarity with construction activities.
Assessing material requirements, ordering and delivery scheduling.
Tracking progress and costs.
Capturing feedback and as-installed information, again, increasingly using mobile devices and tablets.

Where changes are made, or new information is acquired, the virtual construction model must be updated quickly so that the impact on subsequent works can be properly considered.

Once the building information model has been verified against what has actually been constructed, it should be handed over to the employer as an as-constructed asset information model (AIM). A point cloud or LiDAR survey may be carried out to confirm the completeness of the as-constructed model.

The asset information model is the model that compiles the data and information necessary to support asset management, that is, it provides all the data and information related to, or required for the operation and maintenance of the completed development.