In the first of a series explaining the fundamentals of BIM, Stefan Mordue, co-author of BIM for Dummies and a technical author at NBS, explains the basic principles of PAS 1192.
Speaking in 2011, Francis Maude, the then minister for the cabinet office, announced that that the adoption of BIM would put the us at the vanguard of a new digital construction era and position the UK to become the world leader in BIM.
When the government embarked on its four-year BIM strategy, it had a clear hypotheses. As a client the government can derive significant improvements in cost, value and carbon performance through the use of open shareable asset information and implementing a strategy that focused on the production, exchange and use of data and information as the means of delivering this.
It looks as if Maude’s bold statements are now coming to fruition, as the UK has risen to the forefront in BIM standards and adoption worldwide. However, while the UK’s global lead on BIM may not always remain, adoption of its standards such as PAS 1192 are going global as work has commenced to turn this into an ISO standard.
What is PAS 1192?
At the core of BIM is collaboration. To enable collaborative ways of working, everyone needs to be working from the same hymn sheet, or in this case from the same consistent set of standards. PAS 1192:2 or to use its full name – specification for information management for the capital/delivery phase of construction projects using building information modelling – is a key supporting document for achieving Level 2 BIM.
PAS, which stands for publicly available specification (although early examples were titled product approval specification), is a sponsored fast-track standard and is a mechanism to get a much-needed standard into an industry in a short space of time.
It can have a development time of around nine months as opposed to a British standard (BS) which takes much longer. The reason being is that while a PAS invites comments from interested parties it does not necessarily incorporate them.
PAS 1192:2 has been made available to the industry for free as a digital download (a paper copy will cost you £50). Not all PAS documents are free, however – in this instance it has been sponsored by the Construction Industry Council and is available from http://shop.bsigroup.com/navigate-by/pas/pas-1192-22013/.
At the core of PAS 1192:2 is BS 1192. This British Standard has been around for some time, originally being published in 1998 and then revised in 2007. It describes itself as a “best practice method for the development, organisation and management of production information”. Essentially it provides a common way to approach collaborative working and provides common naming conventions. This has recently been updated to BS 1192:2007+A1:2015 and is being updated to align with PAS 1192:2. It is now available for free.
Think of PAS 1192:2 as a framework which is aligned to the stages of work. The document introduces you to the project information model (PIM) which is a combination of graphical data (geometry) non-graphical information (attributes) and associated documentation (such as a specification). Information increases and matures during the design and construction stages before the PIM is handed over to the client to allow them to operate their new asset. Information is then delivered to the client by the information manager along the way via information exchanges.
These information exchange points are usually defined within the employer’s information requirements (EIR) and are important as it enables the client to make informed decision along the way.
In contrast to PAS 1192:2, its sister document PAS 1192:3 considers the operation and in-use stages. This document looks at the asset information model (AIM) which is a single source of validated and approved information that relates to the built asset which can be used by clients, end users, and facility managers during to the operation and in-use phases.
Common data environment
If we refer to the Bew-Richards maturity model, (or as it is affectionately known, “the wedge”) Level 2 BIM is described as collaborative rather than integrated, which is the Level 3 description. Collaborative BIM is actually an assembly of distinct, interlinked domain models (rather than a single model) each produced by individual contributors. Known as federation this series of models gives a completed picture of the asset. PAS 1192 refers to the central place in which these models and information are brought together as the Common Data Environment (CDE).
BIM for Dummies, published by Wiley, and co-authored by David Philp, Stefan Mordue and Paul Swaddle, is available from 30 October.