BimServices: Supporting COBIE2 with IFC
by Nicholas Nisbet MA (Cantab) DipArch (UNL) - AEC3 and E. William East, PE, PhD - Engineer Research and Development Center, U.S Army, Corps of Engineers
For some of the information exchanges, there is a need for simple data formats that can be used for manual data entry or manual inspection by users. In the case of the Construction Operations Building Information Exchange (COBie2) a spreadsheet format is required as the deliverable format. COBie2 is suitable for use at a number of specific milestones of the project development:
- Architectural Programming Phase
- Architectural Design Phase
- Coordinated Design Phase
- Construction Documents Phase
- Construction Mobilization Phase
- Construction 60% Complete Phase
- Beneficial Occupancy Phase
- Fiscal Completion
A foundation of all buildingSMART projects is that the required information exchanges can be mapped onto the Industry Foundation Class (IFC) model. The design process used by the buildingSMART has ensured that the COBie2 spreadsheet format is consistent and interchangeable with the IFC FM-10 Model View Definitions for Architectural Handover. To demonstrate this interoperability between COBIE spreadsheet and IFC implementations a command line program has been written to translate between the IFC-Express, ifcXML, and the COBie2 spreadsheet format. This program can be used to translate from IFC to COBie2 spreadsheet or from the COBie2 spreadsheet to IFC.
The primary functions addressed by BimServices are:
Converting between IFC files and COBie2 files.
Converting between IFC files and IFCXML files.
Reporting on the objects and properties within an IFC file.
Highlighting issues from IFC files as reports.
Comparing the objects and properties of two IFC files.
Selectively reducing an IFC file by the removal of data not required for a specific information exchange.
Testing an IFC building model against an IFC constraint model by using an appropriate set of dictionaries.
Functions NOT addressed by BimServices as supplied—because they would require the authoring of specific configurations—include:
Converting between other spreadsheet formats.
Converting between other XML formats
Functions NOT addressed by BimServices because they are out of scope:
Converting using versions of IFC other than IFC2x3.
Round tripping of data.
BimServices uses an IFC model parser contained in the IFC Engine. The IFC Engine component is available as shareware and may be found under the resources link at the bottom of this page. This program must be legally installable prior to using BimServices, though a copy is provided in the package.
Since the majority of users in the capital facilities industry will have MS Office 2003 (or better) available, this was selected as the required spreadsheet format. The Microsoft Excel 2003 XML Spreadsheet is the format used with COBie2 spreadsheet files must be saved as Excel 2003 XML Spreadsheets to work with BimServices. Users of more recent MS Office products have the option of saving as a 2003 XML Spreadsheet.
BimServices Transform1 uses the MSXML XSLT translator program integral to Windows XP and later Microsoft-based operating systems. The mappings used (the _asCOBie 2.xml.xsl and _fromCOBie2.ifcxml.xsl files) are provided as part of the installation package. BimServices Transform1 is open to users developing, tailoring or improving these transformations. To speed the process of transforming between ifcXML and COBIE MS-Excel XML the reader may substitute a commercial XML processing program.
Warranties and Support
BimServices was developed as a demonstration, not as a commercial product. Commercial version of the translators may eventually be provided by private industry, but until that time users familiar with command line programs are welcomed to download and use BimServices. While the author of this program and the associated IFC Engine have verified its performance in conjunction with the testing conducted during the December 2009 BIM Information Exchange Demonstration, there is no warranty or technical support provided with this product. No warranty is given on the efficacy of BimServices in its use with any particular BIM application or IFC project model.
A user manual for the ifcCOBIE program is available with the installation. Peer-to-peer technical support of BimServices may be available from the author firstname.lastname@example.org. Note that large models created from full IFC 2x3 Coordination Views that include the entire building and component geometries may take more than one hour to process. For parsing large models machines with the fastest CPU and maximum accessible memory should be used.
TO TRANSFORM AN IFC MODEL INTO A COBIE2 SPREADSHEET
transform1 -s _asCOBIE2.xml.xsl Model.ifc
(creates Model_asCOBIE2.xml spreadsheet)
TO TRANSFORM A COBIE2 SPREADSHEET INTO AN IFC MODEL
transform1 -s _fromCOBIE2.ifcxml.xsl Spreadsheet.xml
(creates Spreadsheet_fromCOBIE2.ifc model)
TO REVIEW THE ISSUES EMBEDDED IN AN IFC MODEL AS A WEB PAGE
transform1 -s _Issues.xhtml.xsl Spreadsheet_fromCOBIE2.ifc
(creates Model_fromCOBIE2_Issues.xhtml web page)
BimServices Microsoft Installer Package (MSI) is available from aec3.
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