A well planned content management strategy is essential for BIM-ready organisations, writes Nick Harris from design technology supplier and consultancy CADline
If the move to model-based design is the first stage in developing a Building Information Modelling (BIM) capability, the significance of the digital components used to assemble those models cannot be overstated.
Products such as Autodesk Revit, AutoCAD Plant 3D and AutoCAD Civil 3D are orientated around the selection and arrangement of virtual components and assemblies that exhibit the properties and behaviours of their real world counterparts.
Revit uses predefined libraries of components categorised by function and association, while AutoCAD Plant 3D uses standardised specification-driven catalogues.
As such, a BIM model is only as good as the BIM component library used to create it.
Fortunately the leading BIM products are all delivered with a library of well-defined components or specifications that allow the new adopter to start to become productive without too much additional effort.
However, for building design products especially, these vendor-supplied libraries quickly become limiting and the increasingly proficient user will want to extend the libraries to use less generic, more specialised components.
All mainstream BIM design products will allow fast modification of existing components or the creation of entirely new ones as a project requires, often without leaving the design environment and with an emphasis on upholding productivity. However, this ability to modify a BIM component library, potentially without restriction, presents a new set of challenges. What if one user modifies a component that is used by the rest of the organisation to the detriment of the organisation as a whole? How would you know if that modification has been made? How do you stop multiple users creating the same component or share components used in other projects?
Content management is not a new activity for a design organisation using CAD but the importance and relevance of block or symbol libraries was often diminished where the deliverable was a physical or electronic document, formatted to be consumed by the human eye.
This aspect of planning BIM adoption will have many associated considerations. Where will you store your core content library? A network location accessible to all makes sense but what about those consumers of the content that use laptops and sometimes work away from the network?
Who should be able to create content? Should it just be those who have been trained? But won’t that slow the users down if they have to find a content author when they need something new?
How about restricting the submission of new or amended components to nominated librarians who can check their quality and add them to the organisational library? This tends to be the approach that many organisations take when they start using Revit and is sufficiently robust to satisfy minimum data control requirements.
However, a whole new set of responsibilities need to be added to someone’s busy workload and as more projects produce a BIM deliverable that workload becomes more significant.
Furthermore, as components are refined, version control, relevancy and currency all become content management considerations. There are a number of commercially available content management solutions.
Then there is the question of intent: What is the purpose of creating the BIM model and where is the information derived from it destined to be employed?
A workflow that does not require collaboration with other BIM capable organisations has different requirements of its BIM component library than one that participates in a fully realised BIM enabled supply chain. For example, an architect specialising in domestic projects whose primary deliverables are visualisations provided to the client and 2D drawings delivered to the builder, will optimise its components for producing that information in that format and will probably only need to comply with a basic standard.
Conversely a building services engineer engaged in a centrally procured government project will be required to deliver very specific datasets from the BIM model, which means the component library will need to conform to some very specific industry standards.
This variation in relevance for the same digital building component can be quantified by the concept of ‘Level of Development’ (LOD). At its simplest, LOD in a product like Revit can apply to the display of the geometry at different scales depending on how the output is formatted.
Ductwork design in Revit MEP producing documentation at a scale of 1:100 will only need a coarse representation of the run with little detail around the flanges, fixings and hangers. With detailed documentation, where the views are produced at a scale of 1:5, it is preferable to show the joints in a much finer detail which does include the flange thickness and fixing bolts. Therefore the same digital component within a BIM model needs to support varying levels of detail depending on its application.
LOD, a term used by American Institute, takes this concept further by considering what specific information is attached at each level of development. The information attached to conceptual models is mainly concerned with geometry and materials, where as a model used to create working drawings needs detailed information about the manufacturer and specification of individual components.
An organisation involved in public projects will need to know about Construction Operations Building Information Exchange (COBie), the schema that can be used for delivering facilities information often directly from a BIM model.
I will not go into detail about COBie here but will point out that to create a BIM model that contains the information required to create a COBie dataset, content must populated with COBie data.
The BIM Task Group, the collection of working parties that are supporting and helping deliver the objectives of the UK government’s Construction Strategy particularly around BIM, has a wealth of information on its website, including a template repository aimed primarily at manufacturers wishing to create BIM content that supports COBie data delivery.
Why waste effort on creating BIM content when someone else can do it? As an Autodesk partner that implements design solutions to both the construction and manufacturing industries we have been working hard to help manufacturers understand the value of delivering BIM-ready information to their clients.
We have been able to demonstrate that designers will specify products from suppliers that provide BIM-ready components because of the availability of information and the commitment to the cause those suppliers deliver. It is certainly worth asking suppliers if they are BIM ready or visit one of the dedicated content providers.
The NBS National BIM Library, (nationalBIMlibrary.com) and BIMStore (bimstore.co.uk), are two leading commercial online providers of content in the UK which have an increasingly rich library of content. Autodesk has its own content exchange called Autodesk Seek.
Our advice is to understand what is your organisation’s ultimate BIM deliverable in the short and long term and plan your content management strategy accordingly.
Get a feel for what content is provided with new BIM products; identify where to store content libraries and who will be responsible for maintaining it.
It is important to understand that for many, their library represents intellectual property with as much value as the BIM project information derived from it.