The desire
In a BIM project, the structuring and exchange of information takes place through digital building models. One of the pillars for making BIM possible is the creation of an object type library (Object Type Library -OTL). OTL is a data model designed to ensure that all desirable information about infrastructure objects can be stored in a digital twin. The OTL is prepared by combining information from the various standard specifications (250, 260 and 270) with feedback from experts who deal with these infrastructure objects on a daily basis. The biggest challenge is to establish a model that is widely supported by stakeholders and that there is a consensus on what information should be tracked and which should not.
Geo Solutions in action
BIM implementation plan with guidelines
In order to ensure that the data delivered according to the data model is usable and consistent toward the future, some rules are used in delivery. We find this information in the BIM Execution Plan, created together with all parties of a given project. This BIM execution plan contains the guidelines for correct delivery in terms of Level of Geometry and Level of Information.
Data screening
When data is supplied, it is first screened by the developed DAVIE application (Data Acceptance, Validation and Information Extraction) before it is effectively stored in the databases. This application verifies that the correct file types and syntax have been used and that the supplied data conforms to the classes, attributes and object relationships found in the OTL.
Geo Solutions consultants
A substantive, semi-automated check is then further performed by some GEO Solutions staff employed by AWV. Currently, AWV provides support for the below common formats when submitting data:
- Text based: CSV, JSON, XLS, XLSX, WKT
- Application based: REVIT, AUTOCAD, TEKLA
AWV is preparing to support IFC and GEOJson.
Metadata
For every component in the real world, there is an equivalent class in the OTL. Attributes are attached to such a class, drawn up in consultation with experts. Each attribute can include a different simple or complex dataType. Among others, the following simple datatypes are used: String, Integer, Boolean, … These simple datatypes may possibly have some unit. We call this a quantitative value expressed in, for example: Ampere, Bar, Celsius, meter, … In addition, more complex dataTypes such as a Pick List or a dataType that allows to “nest” other dataTypes are also used. This creates a large, complex data model.
To manage this data model, there is a need for metadata. This metadata includes descriptive text of how to use and interpret the OTL. In addition, a schematic representation of how the data model of the OTL, which is formatted in Enterprise Architect, behaves in SQLite was also prepared.
Advice and expertise
GEO Solutions’ consultants on AWV’s BIM Team are co-leading the rollout of BIM in AWV’s public contracts, supporting AWV employees and project partners in all aspects of BIM in infrastructure projects. This ranges from embedding the AWV BIM guidelines in the specifications, to general BIM project follow-up and follow up coordination meetings, to technical knowledge transfer, data verification, training, coaching and data migration from existing databases to the new OTL-compliant infrastructure. GEO Solutions consultants assist AWV in data exchange expertise and work as a team to address the innovative challenges posed by BIM.
The value
The result of a well-functioning OTL is that employees can work in a unified BIM-focused way in the future. This will ensure better cooperation between all AWV project partners who will all speak the same language. This will lead to quality projects. Management, maintenance and operation will be able to be done more efficiently. Information will flow more easily and be shared across the entire life cycle: from investment to management and maintenance. It will also be possible to detect and resolve design flaws and technical problems more quickly, minimizing failure costs and delays on site.
