Wawan Solihin

An ontology-based approach for developing data exchange requirements and model views of building information modeling

Each domain industry requires the detailed specifications for sharing and exchanging building information models throughout the design, construction, and operation phases. Industry Foundation Classes (IFC) Model View Definitions (MVDs) specify required information for exchanges of building model data among building project experts. The data involves the identification of model semantics shared by two or more applications. However, since no robust standard for defining building semantics and requirements for data exchange has been agreed upon, information embedded in domain-specific MVDs are generated separately and are vague in scope, which results in a lack of consistency. In addition, the Information Delivery Manual (IDM) that includes exchange specifications needed for each exchange process of a product model is manually defined in a paper-based document. Because there is no clear logical link between the units of information in the exchange requirements of an IDM, and those of MVDs, the mapping that translates requirements of an IDM into ones of an MVD is open to various interpretation, without semantic and logical consistency. Such challenges might result in redundant requirements and rules for data exchange that are not supposed to be handled in the process of MVDs. To ameliorate this situation, this research proposes the new approach of formalizing domain knowledge and defining accurate data modules for model views. To achieve this goal, the authors employed ontological principles for generating an IDM for the precast concrete domain and for linking its MVD with formal information models. The formalized structure of domain knowledge is expected to support defining explicit data modules and developing manageable relationships among entities using semantic reasoning so that domain professionals and software vendors can identify the intents of the requirements of mapped MVDs and keep track of mapping problems. Moreover, to integrate IDM and MVD development processes, the ontology-based IDM is parsed and translated from OWL/XML to mvdXML, which automatically generates MVD documentation in the IfcDoc tool.

Toward robust and quantifiable automated IFC quality validation

We identify quantifiable rules for testing a good quality IFC file.We define classifications of the validation rules including syntax and semantics.We outline initial list of validation rules covering all aspects of IFC testing.The validation rules include well defined rules for geometry and spatial related tests.We propose rules for automated IFC import testing. The use of IFC as a standard format in exchange processes has been increasing as the industry begins to address the need of interoperability. A current problem with the use of IFC is in the quality of product models. Much effort has addressed this issue in the form of certifications to ensure a minimum quality of exchange requirements for an IFC file. However, even with the recent increasing awareness and effort to improve the quality of IFC files, the process is still too tedious, time consuming and requires manual efforts by experts. Even if those resources are available, there is currently no clear and quantifiable definitions of what exactly is a good quality IFC file. Without such measures, the adoption of IFC as standard exchange format will be hindered and the industry will be left with only restricted alternatives that are mostly vendor dependent. This paper sets out to address this issue in two aspects: first by defining what a good quality IFC model is, and second by proposing rules that can be automated to measure with confidence the completeness and correctness of the IFC model. These two aspects will serve as a starting point toward a more comprehensive and quantifiable measures of the quality of an IFC file. This proposed goal is represented by using well defined and well documented rules collected from various projects the authors had experienced over the years. The rules include all known aspects of IFC, including geometry, which currently requires mostly manual validation. The paper also proposes a method to address import validation that is under-developed compared to the export validation.

A framework for fully integrated building information models in a federated environment

We discuss the importance of the use of federated models in the AECO industry.We highlight shortcomings of the current IFC schema to deal with the federated models.We propose simple yet powerful modification to the IFC schema to support this.We introduced the concept of deferred reference and object snap in.We demonstrated the potential use of the concept for federated models and versioning. The nature of building projects necessitates building models to be designed by various parties representing disciplines in the Architecture, Engineering, Construction and Owner-operator (AECO) Industries. The federated model emerges as the most practical approach to deal with the various models, especially during design stage, construction coordination and beyond. One of the issues with the current approach is there is no real integration between the various models beyond their spatial co-location. This paper proposes a framework to enable fuller integration of otherwise disparate models into integrated models in the federated environment by enabling two critical concepts - deferred reference and an automatic object snap-in. The concepts are applied in a proposed change to an IFC schema and standardized procedure to enable the automatic snap-in mechanism. With these concepts, models could be designed and exported independently as valid, perhaps partial models and yet will remain integrated when they are inserted into the federated model. A prototype system has been developed to show the effectiveness of such integrated models.

The Critical Role of Accessible Data for BIM-Based Automated Rule Checking Systems

This paper proposes a concept of an accessible BIM database that supports integration with geometry enabling simplified and efficient queries of the IFC-based building model. The simplified schema, BIMRL, is shown to be significantly effective for the purpose of an implementation of an automated BIM-based rule checking system. The schema has been shown to successfully work in both traditional RDBMS and the NoSQL graph database. It complements a missing piece in the current research of automated rule checking, which mostly focuses on the formulation and representation of computable rules involving logic, checking algorithm, and parameterization. Even though these present approaches have largely assumed that data is available and easily accessible from a building model, this assumption is typically infeasible in a real-world implementation. Building rules require not only base data explicitly available in the model but also higher level semantic concepts that typically involve multiple relationships and spatial operations, which cannot be captured explicitly in the model. Without addressing this issue, a rule checking system will severely underperform and will be filled with opaque algorithms that act as black-boxes.

In Search of Open and Practical Language-Driven BIM-Based Automated Rule Checking Systems

Significant progress has been made towards BIM-based automated rule-checking systems. There are multiple approaches that show varying potentials as crucial components for open and practical rule checking systems. However, in the current state, we are not yet quite there as they are still several barriers that prevent the needed shift from proof-of-concept to the real-world implementation. This paper reviews various language-based rule checking systems that have been proposed and assesses their potentials and gaps that need to be overcome for them to become practical. It introduces metrics of eleven criteria to analyze various approaches to assess their readiness for the real-world implementations. The criteria cover a wide range of aspects including language expressiveness, ease of use to define a rule, openness, level of maturity, and performance. These criteria help to identify gaps that currently exist that need to be overcome to allow a leap from a proof-of-concept to the real-world implementation. From the assessment, it is obvious that no one single approach is currently capable of covering the entire spectrum of requirements for automated rule-checking systems. The assessment also shows that the possibilities of combining two or more approaches may accelerate the realization of an open and practical language-driven automated rule checking system.

Modularized BIM Data Validation Framework Integrating Visual Programming Language with LegalRuleML

A building design must satisfy diverse requirements including building codes, owner’s specifications, design guidelines, and project requirements. In addition, there is a growing need for an automated design evaluation process involving intelligent checking and reporting capabilities that addresses the inefficiency and error-prone nature of the current manual checking practice. To leverage the automated rule checking procedure, we need to overcome two existing key challenges, which are the inherent complexity of rules and the impracticability of checking methods. To address these challenges, this research proposes a node-based visual language approach integrated with the emerging open standard LegalRuleML, which allows the flexibility in defining and executing design rules in a machine-readable and implementable format. The approach effectively facilitates the entire rule-checking process including the rule interpretation from natural language-based requirements to machine-readable forms, rule categorization, rule parameterization, and checking execution with a BIM model. The LegalRuleML-based visual programming language approach for rule checking will help automatically and iteratively evaluate the quality and defects of information conveyed in a given building model interactively as an essential part of design process.