## 5 Summary of the Interoperability Tests
### Use of IFC 2x3 Coordination View 2.0 (CV 2.0)  
The first export/import test, which aimed to verify both the horizontal and vertical interoperability, was carried out on the most popular IFC format, IFC 2x3 CV 2.0. The outputs of the tests are described below for each sending software:  
* **Autodesk Revit. *
* The CAD model generated in Revit was exported as an IFC file and imported into other environments. Due to the number of different settings (i.e., additional export content, level of details, and advanced settings) requested by the export interface, this task was not trivial; some knowledge about the way the receiving systems could handle IFC entities may have improved the exchange process, according to the software guide. Concerning the horizontal interoperability, the imported geometrical model agreed with the original model, while the material data was limited to only the material name. In terms of the parameters, some differences were found. The self-test showed that the section dimensions were not fully editable (i.e., only the length could be changed but not the section size). Even some dimensions, such as the relative location of columns, could not be directly edited. On the other hand, the model imported in Allplan and ArchiCAD was fully interoperable. In Edificius, the IFC file had to be imported into a new project, but it allowed us to edit very few simple features, such as colour, transparency, snap, and so on; the imported file was essentially a reference model. Among the CAE environments, geometry issues occurred in RSA and SAP2000: beams appeared 90\({}^{\circ}\) rotated around their axes (Figure 2a). The analytical model generated in RSA from the geometrical model showed disjointed elements, requiring additional editing in the receiving software (Figure 2b). As far as RFEM was concerned, the software was unable to import the four columns due to their different representation type adopted by Revit; more details about this aspect are provided in the discussion section later. The material data could be associated with the objects only if their imported name matched the internal material library. ModeSt, on the other hand, could correctly read the model in terms of geometry and material information content, while some parametric features were lost (the parametric locations of the elements). Similarly to ModeSt, Tekla Structures worked well, and with the use of the convert IFC object command, the user could easily modify all the geometric parameters. Steel material was associated with all the components originally defined as reinforced concrete. Edilus could correctly import the model, but no parametric changes were allowed. * Thanks to the possibility to choose pre-configured IFC settings for different input/output software, the end user could customise the export file in ArchiCAD based on the destination environment. For the horizontal interoperability, there were no significant differences compared with the previous case (from Revit); thus, the same scores were applied. However, the self-test worked better than before, as the software also recognised the assigned materials of the objects (in other cases, only the material name was provided). With IFC 4, a new material (with customised mechanical properties) was also fully recognised. Concerning the vertical interoperability response, the export template for structural analysis was able to convert the geometry in only the structural elements, thus avoiding including unnecessary geometrical data and other elements such as furniture, finishes, etc. The global behaviour was better than the Revit result. RFEM could correctly read the IFC model in terms of geometry and materials. The section type and materials parameters could be edited very quickly and in detail. However, the object sizes were not editable in as straightforward a manner as for the native objects. SAP2000 interpreted the beams as elements rotated 90\({}^{\circ}\) with respect to the original objects. For EdiLus, the same considerations as for Revit applied.