BIM is essentially "the process of generating and managing information about a *building during its entire life cycle".
*However the term BIM is to an extent limiting and is not all about buildings with walls and roofs. It’s more about the verb to ‘build’ rather than the building itself. This includes roads, bridges, railways, process plants and infrastructure.
A Definition
ICE views BIM as the purposeful management of information through the whole life cycle of an infrastructure asset. Thus, BIM is a managed approach to the collection and exploitation of information across the life cycle of a built environment asset – which keeps the needs and overall purpose of the asset at the fore. At its heart are computer-generated models connecting all graphical and tabular information about the design, construction and operation of the asset and associated documents. BIM allows design options to be explored digitally. Design changes are quicker and cheaper to enact when compared to traditional design tools. It is the technological and process successor to CAD and 2/3D drawings and creates data files or ‘objects’ of physical components and spaces to produce a sophisticated 3D models, which contain both graphical representation of the asset, but more importantly details of all its associated information that can be reused.
It is important to note that BIM itself is not a single software application but is the use of software tools embedded in a process to manage data throughout the lifecycle of an asset from procurement through operational management and changes. For this reason there is often controversy over what the ‘M’ in BIM means – we recognise that it covers two interchangeable aspects Modelling and Management of the key component Information.
The term Building often gives rise to confusion limiting the application of BIM to Architecture and physical buildings however in the context of the industry Building should be taken as the verb to build rather the noun a building.
Data generated by the BIM process can contain information on detailed dimensions, component-placement, material specifications, structural performance, fire rating, “U” values, and carbon content (both embedded and operational), cost, maintenance schedules and performance etc. In effect, the asset is built ‘virtually’ using these exact data-rich objects from which plans and drawings can be extracted. It is a distinguishing feature of BIM that no traditional ‘drawings’ are involved in the creation of the model and the data related to the model - which is not present in static representations of the structure - can be analysed and selectively made available to meet demands and function across the whole life cycle of the structure. Drawings are a reporting output of the process, not the inherent process itself (although the model will supersede ‘drawing’ over time). A BIM model provides clear accessible information which can then be exploited and used to manage the construction and management of structures which – if exploited correctly – can lead to significant efficiencies and improved delivery of client ‘value’ in construction and, in particular, cost saving.