Nani, G; Mensah, I and Adjei-Kumi, T (2017) Duration estimation model for bridge construction projects in Ghana. Journal of Engineering, Design and Technology, 15(6), pp. 754-777.
Abstract
Purpose A major concern for construction professionals at the rural road agency in Ghana is the problem of fixing contract duration for bridge construction projects in rural areas. The purpose of the study was to develop a tool for construction professionals to forecast duration for bridge projects. Design/methodology/approach In all, 100 questionnaires were distributed to professionals at the Department of Feeder Roads to ascertain their views on the work items in a bill of quantities (BOQ) that impact significantly on the duration of bridge construction projects. Historical data for 30 completed bridge projects were also collected from the same Department. The data collected were executed work items in BOQ and actual durations used in completing the works. The qualitative data were analysed using the relative importance index and the quantitative data, processed and analysed using both the stepwise regression method and artificial neural network (ANN) technique. Findings The identified predictors, namely, in-situ concrete, weight of prefabricated steel components, gravel sub-base and haulage of aggregates, used as independent variables resulted in the development of a regression model with a mean absolute percentage error (MAPE) of 25 per cent and an ANN model with a feed forward back propagation algorithm with an MAPE of 26 per cent at the validation stage. The study has shown that both regression and ANN models are appropriate for predicting the duration of a new bridge construction project. Research limitations/implications The predictors used in the developed models are limited to work items in BOQs only of completed bridge construction projects as well as the small sample size. Practical implications The study has developed a working tool for practitioners at the agency to forecast contract duration for bridge projects prior to its commencement. Originality value The study has quantified the relationship between the work items in BOQs and the duration of bridge construction projects using the stepwise regression method and the ANN techniques.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Ghana; artificial neural network; duration; bridge projects |
| Index terms: | rural area, bills of quantities, duration, bridge project, in-situ, construction professional, sample size, aggregate, back propagation, independent variable, Ghana, estimation, regression model, feed forward, agency, bridge construction, methodology, validation, questionnaire, practitioner, relative importance index, artificial neural network |
| Subjects: | statistical analysis, infrastructure and transport systems, sociology, building construction, project controls, land use and regional development, infrastructure engineering, professional development, Geography, research methods, algorithms, financial and cost management, modelling and simulation, practitioner, control systems, materials science, research design and methodology, risk assessment, data collection methods |
| Topics: | Time Control, Digital Applications, Urban Studies, Risk Management, Roles and Professions, Cost Management, Engineering Principles, Information Management, Research Practice, Geographical Context |
| Descriptive scope: | 4 PCTA |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here