We are writing a white paper about GIS for Facilities Management that should be released at some point in the April time frame. Over the weekend, I was working on a section about the relationship between GIS and BIM in this context. I would really like to get your feedback on whether this perspective makes sense to you. Please let me know your thoughts.
GIS Complements BIM
One of the most exciting technologies to evolve in the past decade for those involved in the design and construction phases of buildings is the concept of building information modeling. Wikipedia defines Building Information Modeling as: “the process of generating and managing building data during its life cycle. Typically it uses three-dimensional, real-time, dynamic building modeling software to increase productivity in building design and construction. The process produces the Building Information Model (also abbreviated BIM), which encompasses building geometry, spatial relationships, geographic information, and quantities and properties of building components.” In the last decade, software vendors including Autodesk, Bentley, Graphisoft, and others have built specific software products to implement the concepts of building information modeling in powerful new three-dimensional and object-oriented software architectures. The broader industry has also come together to form the Building Smart Alliance in order to ensure data interoperability between the major software platforms. The building Smart alliance has published a data interchange standard known as the National BIM standard which describes a structured XML format for the purpose of interchanging BIM data.
It would be hard to overstate the significance of BIM to the architecture engineering and construction community. This technology allows building designers to document their designs in a very detailed way, to detect potential conflicts between different building systems, and to communicate that detailed design intention to those responsible for constructing the building in a very detailed way. Because of the efficiencies gained through the adoption of this technology and the implicit savings in both cost and schedule that can be gained through systematic adoption of this technology, BIM is becoming very widely accepted by the architecture engineering and construction communities and is often being required now for many government and higher education building design and construction projects.
Despite the tremendous value that BIM represents for building design and construction, there are some significant limitations to the technology that make it less ideal for supporting the operations and maintenance phases of the building lifecycle. For example:
- To begin with, much of the data that is necessary for managing building performance is not known and therefore cannot be developed when the original BIM is being created during the design phase. For example, space assignment and occupancy - critical considerations for any building manager - are almost never known at the time of building design. Furthermore, there are not data structures within most BIM systems that would allow this type of information to be maintained on an ongoing basis. Therefore, this data must be created and maintained after building commissioning in a system other than BIM.
- The vast majority of our existing building stock was built before the advent of BIM technology. The challenges of creating a BIM for an existing building are significant and expensive to solve. While the business value proposition of BIM in the design and construction phase has now been reasonably well proven, the value of creating a BIM for existing buildings is so far much more tenuous. For the foreseeable future, technologies deployed for the operations and maintenance of existing buildings are likely to be other than BIM.
- BIM does not scale well to large facilities or portfolios. Practitioners of BIM have reported significant challenges in creating models of large buildings or collections of buildings. These challenges are often performance related. Because the BIM is attempting to model the built environment in a very high level of detail and at a very precise scale, the overall model can quickly grow to the point where it overwhelms available system resources. For many facility managers this is a critical problem. Their responsibilities often span large campuses, cities, or the globe. Facilities managers have a definite need for a solution that can scale from the world to the widget.
The good news is that GIS can be used to complement and extend the capabilities of BIM. While a GIS implementation will almost never be as finely detailed nor as semantically rich as a construction BIM, we can harvest a lot of information from a BIM if it is available and create a system of geographic reference for many of the problems that face facilities managers on a day-to-day basis. Furthermore, we can create links in the GIS that reference back to the BIM for those cases when highly detailed information is required. This blending of technologies allows us to create information systems that perform well at large geographic scales, conform to enterprise IT standards for security, adapt to a wide variety of original data sources, and still allow us to link back to highly detailed building information models when those data sources are available.
In this view then, GIS does not replace nor compete with either CAD or BIM. Rather, GIS is used in an interoperable way to harvest information from a variety of data sources to create systems that perform well at large geographic scales and yet linked back to the source systems when highly detailed information is necessary for specific requirements.