Madhav Prasad Nepal

Ontology-Based Feature Modeling for Construction Information Extraction from a Building Information Model

A building information model (BIM) provides a rich representation of a buildings design. However, there are many challenges in getting construction-specific information from a BIM, limiting the usability of BIM for construction and other downstream processes. This paper describes a novel approach that utilizes ontology-based feature modeling, automatic feature extraction based on ifcXML, and query processing to extract information relevant to construction practitioners from a given BIM. The feature ontology generically represents construction-specific information that is useful for a broad range of construction management functions. The software prototype uses the ontology to transform the designer-focused BIM into a construction-specific feature-based model (FBM). The formal query methods operate on the FBM to further help construction users to quickly extract the necessary information from a BIM. Our tests demonstrate that this approach provides a richer representation of construction-specific information compared to existing BIM tools.

Downtime model development for construction equipment management

Downtime (DT) caused by non-availability of equipment and equipment breakdown has non-trivial impact on the performance of construction projects. Earlier research has often addressed this fact, but it has rarely explained the causes and consequences of DT – especially in the context of developing countries. This paper presents a DT model to address this issue. Using this model, the generic factors and processes related to DT are identified, and the impact of DT is quantified. By applying the model framework to nine road projects in Nepal, the impact of DT is explored in terms of its duration and cost. The research findings highlight how various factors and processes interact with each other to create DT, and mitigate or exacerbate its impact on project performance. It is suggested that construction companies need to adopt proactive equipment management and maintenance programs to minimize the impact of DT.

Current research trends and application areas of fuzzy and hybrid methods to the risk assessment of construction projects

Abstract Fuzzy and hybrid methods have been increasingly used in construction risk management research and this study aims to compile and analyse the basic concepts and methods applied in this field to date. A content analysis is made of a comprehensive literature review of publications during 2005–2017. It is found that the nature of complex projects is such that most risks are interdependent of each other. Therefore, a fuzzy structured method such as the fuzzy analytical network process (FANP) has frequently been used for different complex projects. However, the application of FANP is limited because of the tedious and lengthy calculations required for the pairwise comparisons needed and an inability to incorporate new information into the risk structure. To overcome this constraint, a fuzzy Bayesian belief network (FBBN) has been increasingly used for risk assessment. Further project-specific studies based on FBBN are recommended to justify its broader application. Beyond fuzzy methods, the Credal network – an extended form of Bayesian network- is found to have potential for risk assessment under uncertainty.

Automated extraction and querying of construction-specific design features from a building information model

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BIM and PLM: Comparing and Learning from Changes to Professional Practice Across Sectors

This paper explores the effects of PLM and BIM on professional practice. It draws on existing literature documenting the experiences of both communities of practice to explain shifts in professional boundaries. A review of case study based literature compares the nature of changes triggered by PLM and BIM relative to the new activities, roles/responsibilities and knowledge competencies, and supply chain relationships. The paper synthesises these changes and reflects PLM and BIM experiences against each other so as to contrast the continuing evolution of professional practice and lessons learned.

Querying IFC-Based Building Information Models to Support Construction Management Functions

The design and construction community has shown increasing interest in adopting Building Information Models (BIM). While the richness of design information offered by BIM is evident, there are still tremendous challenges in getting construction-specific information out of BIM, particularly from IFC-based product models. This paper describes our approach for querying construction-specific design conditions from an IFC-based model. The approach involves: (1) the formalization of construction-specific design conditions as an ontology of product features, (2) the automated generation of feature-based product models for a particular construction domain and function, and (3) a formal specification that supports user-driven queries of the feature-based model. This approach allows practitioners to answer a broad range of user-customizable queries in support of different construction management functions. It also transforms designer-focused IFC-based models into constructionfocused, feature-based models.

Development of a Safety Inspection Framework on Construction Sites Using Mobile Computing

AbstractSite safety inspection is an essential task to ensure that construction operations are carried out in a safe manner, in accordance with relevant health and safety policies and standards of a particular jurisdiction. It is also critical to the smooth execution, monitoring, and controlling of construction activities. The evidence gathered from construction experts as well as from previous studies suggests that the efficiency and effectiveness of current inspection processes are less than satisfactory. This paper reports an Australian research project that develops an innovative safety inspection approach to incorporate mobile computing technologies into safety inspection processes in order to facilitate more effective data collection, processing, and control practices. The paper also discusses the interview results of safety practitioners about the proposed inspection approach. The approach was implemented through the development and test of a prototype mobile inspection tool. The feasibility and us...

Drivers of the accuracy of developers’ early stage cost estimates in residential construction

Purpose – Preliminary cost estimates for construction projects are often the basis of financial feasibility and budgeting decisions in the early stages of planning and for effective project control, monitoring and execution. The purpose of this paper is to identify and better understand the cost drivers and factors that contribute to the accuracy of estimates in residential construction projects from the developers’ perspective. Design/methodology/approach – The paper uses a literature review to determine the drivers that affect the accuracy of developers’ early stage cost estimates and the factors influencing the construction costs of residential construction projects. It used cost variance data and other supporting documentation collected from two case study projects in South East Queensland, Australia, along with semi-structured interviews conducted with the practitioners involved. Findings – It is found that many cost drivers or factors of cost uncertainty identified in the literature for large-scale ...

Defining Sustainability Requirements for Design-Build (DB) Contractor Selection in Public Sector Projects

The design-build (DB) delivery system is an effective means of delivering a green construction project and selecting an appropriate contractor is critical to project success. Moreover, the delivery of green buildings requires specific design, construction and operation and maintenance considerations not generally encountered in the procurement of conventional buildings. Specifying clear sustainability requirements to potential contractors is particularly important in achieving sustainable project goals. However, many client/owners either do not explicitly specify sustainability requirements or do so in a prescriptive manner during the project procurement process. This paper investigates the current state-of-the-art procurement process used in specifying the sustainability requirements of the public sector in the USA construction market by means of a robust content analysis of 40 design-build requests for proposals (RFPs). The results of the content analysis indicate that the sustainability requirement is one of the most important dimensions in the best-value evaluation of DB contractors. Client/owners predominantly specify the LEED certification levels (e.g. LEED Certified, Silver, Gold, and Platinum) for a particular facility, and include the sustainability requirements as selection criteria (with specific importance weightings) for contractor evolution. Additionally, larger size projects tend to allocate higher importance weightings to sustainability requirements. This study provides public DB client/owners with a number of practical implications for selecting appropriate design-builders for sustainable DB projects.

Evaluations of BIM: Frameworks and Perspectives

This paper examines the evaluation of BIM-enabled projects. It provides a critical review of the three main areas of measurement, namely technology, organization/people and process. Using two documented case studies of BIM implementation, the paper illustrates the benefits realized by project owners and contractors, and illustrates a lack of attention relative to contextual factors affecting the adoption and deployment of BIM. The paper has three main contributions. First, it identifies and discusses the lack of and difficulty surrounding standardized assessment methods for evaluating BIM-enabled projects. Second, it proposes a conceptual model that includes contextual attributes and demonstrates how the proposed framework reaches beyond simple evaluation to encompass the documentation of BIM’s benefits, lessons learned, challenges and adopted solutions. Third, it shows how the framework can account for existing business processes, organizational process assets, and enterprise level factors. The paper aims to provide a conceptual basis for evaluation and a starting point for benchmarking.