Interoperability for BIM: a structural engineering viewpoint
In construction projects there are always many parties involved; the project owner, architects, engineers, contractors, authorities, suppliers, etc. "Many parties" mean a lot of redundant communication and repetitive transfer of data (design review and changes, details, bill of material …). An effective method of gaining efficiency and improving quality in the construction process is to make use of digital sharing of data. This is the essence of the BIM (Building Information Modeling) process and must prevent re-entry of data; this process is also described as Product-based Model Design. Most software vendors have implemented methods to share the data of their models with other parties.
But the question remains: are the available technologies effective enough from the viewpoint of the structural engineers? In this paper, we discuss the various levels of interoperability, the position of the structural engineer in the interoperability processes, the practical implementations and our viewpoint. For a correct understanding of this paper, it is assumed that the construction project is in an advanced stage (execution planning); the interoperability between architects and engineers and others will then bring maximum benefits.
Interoperability in general
There are several levels of interoperability.
* The basic level is to enable users to export and import data in their application software; e.g. a CAD application – let us say for reinforcement drawings – must be able to read the design data from a CAE software – the required necessary reinforcement as in structural members. AutoCAD and Revit® Structure, both Autodesk products, interoperate with import/export of files. Likewise the CAE application Scia Engineer imports the DWG files as a grid for modeling or even as a background for reviewing. Allplan (Nemetschek) does also import required information’s from other structural packages. In most cases the data exchange concerns pure geometrical non-intelligent data (points, poly-lines, planes, 3D volumes). Each software has its proprietary data storage, which imposes that this interoperability is from one program to another. The longtime existing technique of import/export requires manual interaction to place correctly the imported data. Every time changes or revisions are required, the import/export operation has to be redone. For huge projects with several thousands of drawings, this is an impractical working method. Adding the fact that different parties use different products, this level of interoperability becomes cumbersome.