Legend has it that the CAD, BIM and GIS tribes don’t play well together – but here’s a way forward

David Philp

There is legend of a primal saga between three great information tribes: CAD, BIM and GIS. Each of the three tribes has their own traditions and use different technologies and standards. They speak in different languages and describe things differently; origins and grids often upset them “we don’t like your snake grids” and two of the tribes thought that the earth was, well, flat. They use a cornucopia of digital tools and weapons in the battlefield and generally, they don’t play well together.

The GIS tribe wants to talk to the earth with a strong focus on the geo-location (using real world coordinates) and has a server-focused approach. This tribe typically models existing data or policies and is strong on 2D geometry with a few brave troopers having experimented with 3D mapping. They also talk with the sky using LIDAR UAVs to capture existing data.

The BIM and CAD tribes have a common data environment (CDE) approach. They have a strong emphasis on exchanging information between the various domains in their community. The tribes are also strong on 3D, however the BIM tribe also uses dynamic modelling and digital queries to support what they call ‘plain language questions’ or PLQs and they also like to see a laser scanner in their parishes.

Nevertheless, one day a young Geo-warrior, let’s call him “Dances with BIM” decided to witness what these strange kin folk were doing. He observed that “nothing I have been told about these BIM and CAD people is correct. They are not thieves or beggars, they are not the bogeymen they are made out to be.”

‘Dances with BIM’ brought together the three chiefs and told them that “our tribes have common purpose

He wisely concluded that BIM and CAD are an essential asset data source for the GIS tribe and that GIS is a crucial data source for the BIM and CAD tribes in a spatial context. Combining these information sets allow us to exchange asset and property information at various hierarchy levels and support the decision making processes needed during the asset life-cycle.

‘Dances with BIM’ brought together the three chiefs and told them that “our tribes have common purpose, but to make this work we need to collaborate around the camp fire and create a common language where we can share information and work together.”

You can’t beat a good “once upon a time” but hopefully it highlights the need for collaboration, interoperability and open data standards and that they really are worth fighting for!

At Mace we are committed to an “ethos of BIM platform neutrality, encouraging open workflows which allow all project members to work in a collaborative environment.” As a business we want to use our digital data to transact on and query, these include:

  • BS1192-4:2014 AKA COBie UK 2012
  • Industry Foundation Classes (IFC)
  • XML: landXML(roads) gbXML(energy)

Our vision is to ensure well managed construction data that can be shared across all disciplines, running through the entire asset lifecycle with real time evaluation (an integrated concurrent engineering process). Ultimately using the data to actively to manage and optimise post-occupancy performance and ensure the very best asset management strategy for our customers.

Interoperability is key to this vision and predominately we are using IFC, the data model standard published by BuildingSMART® to share data and exchange across the many different platforms on our projects. However it is a complex schema and generally limited to one direction of travel. Nonetheless, IFC has gone through its growing pains and, as it matures, we really need it to make a “round trip” and deal with infrastructure projects.

Interestingly we are seeing a growing COBie demand from private clients who are essentially looking at their “drop 6” AIM requirements

As a contractor and consultant we are interested more in the end results than how its created: Did we get the data we needed? Can we test and validate it? Can we federate it? Can we do something valuable with it such as digital query?

We are also finding our feet on the Government’s compulsory open standard - COBie UK, but we are mainly generating these data drop deliverables through IFC workflows. Interestingly we are seeing a growing COBie demand from private clients who are essentially looking at their “drop 6” AIM requirements.

Next on our “to do” list, as we start to think about Level 3, are performance data components and how to use suitable schema, telemetry and interface technologies such as SCADA (Supervisory Control and Data Acquisition Systems) to gather real-time data and refine asset performance, ultimately moving from a compliance to value strategy. We are thinking more and more about physical interfaces with hardware such as sensors, the Building Management System (BMS) and we will need to have more “Plugfest” events to test interoperability by physically connecting networked devices.

Irrespective of the level of BIM maturity, the transportation of information and data across the asset life-cycle is really important to us and that’s why mature open data standards are imperative. They help us do this safely, globally and lets everyone play on a level field, especially of SME community.

A collaborative standard being driven by the industry is a good thing.

David Philp is Head of BIM at Mace