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Technology
Eval RSET in TargetSpace
Calculate burnout time of SeparatingElement
YES
burnout time ≥ RSET
Output ‘FAIL’
NO
Figure 2: An executable CDP diagram for re design with C/VM2.
A model view is a subset of a BIM model for a speci c application containing only speci c information needed for that application. For example, there may be separate model views for energy analysis, cost estimating or the compliance audit of a particular discipline such as re safety, structures or mechanical and electrical services.
A model view for compliance audit applications may be referred to as the BCM (building compliance model). For a more speci c application such as the compliance audit of re design, the term FCM ( re compliance model) may be used.
The open standard information delivery manual (ISO 29481-1:2010) provides a methodology for exchange requirements for specifying the information to extract from the BIM model to create the required model view. For standardisation, the task of specifying the exchange requirements for fire safety designs should be undertaken by a professional body such as the Society of Fire Protection Engineers.
Research into automating compliance
BRANZ-supported research at the University of Auckland investigated conventional compliant design processes automated using BIM in conjunction with an open standard regulatory knowledge model (RKM) to represent regulatory requirements and standards.
An RKM representing C/VM2 was developed (see Build 142, Automating compliance audit). To maintain user familiarity with the document, the schema of the RKM was designed to closely mimic the structure of the regulatory document it represents.
Research into automated compliance audit spans 40 years with plenty of emphasis on rule-based representations of regulatory require- ments. These are often hard coded into the compliance audit system so are in exible and costly to change for regulatory amendments.
Human input still essential
One problem with the conventional rule-based approach is that not all regulatory requirements can be represented as rules. For instance, performance-based regulatory criteria often require engineering analysis and simulations to evaluate and therefore cannot be prede ned as rules.
More importantly, human intuition and human expert knowledge often play a signi cant role in design, but they cannot be easily captured as rules. The current research suggests that the key to
automating compliance audit is to strike the right balance between the level of intervention by human experts and automation by machines.
Expert designed work ows executed by process engine
The framework developed during the research incorporates a process/audit engine, ARCABIM, that can execute formal compliant design procedures (CDP) expressed in the open standard BPMN (business process model and notation) (see Figure 1).
The compliant design procedures approach allows a human expert to describe any design procedure graphically using standard BPMN- compliant work ow diagrams similar to ow charts (see Figure 2). Once described correctly, they can then be executed accurately and reliably by a process engine.
The added bene t of having formally documented compliant design procedures is that it helps the peer-review process. It also provides the building consent authority with the formal documentation on selected compliance paths and the philosophy behind a proposed design.
Only basic scripting skills needed
A high-level domain-speci c query language, RKQL, has also been developed in the research. This allows anyone with basic computing skills to write scripting instructions for use with compliant design procedures to extract information from BIM and RKM.
Apart from querying data, RKQL also has the capabilities of instructing ARCABIM to perform certain calculations using the information extracted, to evaluate certain rules or to generate input les for external simulations.
O cial libraries needed
Ideally, an o cial library of compliant design procedures repre- senting the industry standard design practice should be published by a professional body or a government agency.
Similarly, a library of RKMs should be published by a government agency such as the Ministry of Business, Innovation and Employment as a digital equivalent of the paper-based regulatory documents.
Practical application
Once fully implemented, ARCABIM will allow a design engineer to use the compliant design procedures approach to extract informa- tion from BIM and RKM and audit their design automatically for compliance. Having an audited compliant design as part of the building consent submission will help the approval process.
This approach is also applicable to compliance audits against any kind of requirement speci cations including proprietary standards and client briefs.
For more Visit www.cs.auckland.ac.nz/people/jdim006. Johannes Dimyadi is a BRANZ PhD scholar.
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FEATURE SECTION