Yahaya Makarfi Ibrahim

Towards automated progress assessment of workpackage components in construction projects using computer vision

Traditional methods of collecting data on the progress of construction projects often involve human judgement, high costs, and are too infrequent to provide managers with timely and accurate control data. This study proposes a system that aims to address some of these shortcomings through automation. Our first contribution is a framework for the automatic generation of work packages. We describe the conceptual model and develop a prototype implementation, based on the results of a survey designed to capture the current practice of formulating work packages as performed in the industry. Our second contribution is a system that employs computer vision (CV) techniques to report on the progress of these work packages automatically. This is achieved by analysing sequences of digital images acquired regularly by on-site cameras. The result of this analysis, when compared with the expected state of construction, provides progress feedback on the work packages, allowing a project to be monitored more effectively.

The impact of diversification on the performance of UK construction firms

Built upon theories from outside the construction management literature, this study assesses the impact of product diversification on the performance of construction firms in the UK. Performance was measured based on financial ratios of management performance while diversification was measured by the specialisation ratio. The research involved the use of financial data of construction firms covering the period 1995‐2004. The choice of the period is informed by the economic stability during the period and also, by the fact that diversification is a long‐term strategy. The findings indicate that focused firms outperform both moderately and highly diversified firms based on return on total assets (ROTA) and profit margin (PM). However, no performance difference was found between the moderately diversified and highly diversified firms.

Geographic diversification, performance, and the risk profile of UK construction firms

Purpose – Executives are often faced with the challenge of making sound decisions regarding the product and geographic markets into which the company should diversify. This situation is even more glaring with respect to construction companies, owing to the volatile nature of the construction market. The purpose of this paper is to present empirical results on the impact of geographic diversification on the performance and risk profiles of construction firms in the UK.Design/methodology/approach – Published financial data of construction firms covering the period 1995‐2004 are employed in the paper. From this data, extent of geographic diversification, performance, and risk are computed. Firms are grouped based on the extent of diversification into undiversified, moderately diversified, and highly diversified. Performance of these groups is then compared using the t‐statistic based on return on equity (ROE), return on total asset (ROTA), return on capital employed (ROCE), and profit margin (PM).Findings – ...

Modelling building construction durations

Purpose – This paper aims to develop a multivariate model that will be applicable to the Nigeria construction industry. Design/methodology/approach – A self-administered questionnaire survey was used to source information on project scope factors and qualitative factors considered in the study. Principal component regression was used for data analysis and model development, using SPSS 16.0 for windows, while T-test was used for model testing and validation. Findings – The study found that delay in progress payment by owner, lateness in revising and approving design document by owner, delay in delivering the site to the contractor by the owner, change order by owner during construction, complexity of project design, poor site management and supervision by contractors, and rain effect on construction activities are qualitative/non-project scope factors with good predictive abilities. Research limitations/implications – Cost, gross floor area and number of floors were the only quantitative/project scope fact...

Framework for a generic work breakdown structure for building projects

Purpose – The purpose of this paper is to propose a framework for the standardisation of the work breakdown structure (WBS) for building projects. This is based on the premise that buildings in general retain basic elemental options, and that there is a commonality of activities in the procurement of building projects.Design/methodology/approach – To achieve the objective, the general practice of developing the WBS is investigated. This is achieved by means of an industry‐wide questionnaire survey designed to identify the most widely used criteria among UK construction organisations in segregating building works into packages. The survey also investigates the sequencing of these criteria across the WBS hierarchy.Findings – The findings reveal that the most frequently used decomposition criteria in the formulation of WBS for building projects are elements, work sections, physical location and construction aids. The proposed framework is presented as a hierarchical decomposition of a building project based ...

As-built Documentation of Construction Sequence by Integrating Virtual Reality with Time-lapse Movies

Abstract Previous research in the documentation and visualization of as-built construction sequences focused on time-lapse movies. However, a major drawback associated with this approach is the difficulty of interacting with the scene in the image. This does not aid comprehension and interpretation of the job site. In order to address this issue, this research proposes the integration of time-lapse movies with 4D virtual reality (VR) models in a complementary fashion. The VR model provides users with the functionality of interacting and exploring the scene, thereby improving comprehension of the job site. The paper presents the development and implementation of a model for documenting as-built construction operations by integrating time-lapse movies with 4D virtual reality models. First, the conceptual model is developed. Based on this, a Windows-based prototype is developed using Visual Basic.Net as a programming interface. The prototype was implemented and tested on a new postgraduate building at Heriot Watt University. The integrated model adequately captures the as-built sequence of construction and provides a quick and effective means of searching for images in an image database. The system has the potential to support education, claims investigation and dispute resolution.

On the measurement of work in progress using computer vision: a computerised reporting model

Purpose – The desire to improve efficiency has led both academics and practitioners to embrace various technologies to aid managers to discharge their functions. Recently, there has been a growing interest amongst construction researchers on the use of computer vision and image‐processing techniques to automatically capture work in progress. Reported findings are promising; however, those previous studies fall short of providing a reporting mechanism to aid decision making. The purpose of this paper is to develop a reporting model based on progress captured using computer vision.Design/methodology/approach – The paper first presents trends in research relating to use of computer vision in the monitoring of work in progress. It then employs the unified modelling language to present the conceptual development of the model. The computerised reporting model is developed using the visual basic programming language.Findings – The key elements of the model are computations of cost‐schedule variances, payments an...