A Qualitative –Quantitative Model of Cost Estimate for Construction Projects in Yemen

Abstract

Success of construction projects depends on many factors; most important are cost, quality, and time. Concerning cost, the cost estimate can lead the construction firm to huge losses and the correction action cannot be taken. In Yemen, the basic problem that construction firms face is how to make accurate cost estimate for both preliminary and detailed estimates. There were two objectives to conduct this study, which were: to identify the knowledge of cost estimate in construction management, and to obtain mathematical (quantitative) and frameworks (qualitative) models to estimate accurately construction cost in Yemen. In order to achieve these objectives, five questions were asked. The methodology of this study was to use both qualitative and quantitative methods. As well, the adopted strategies were literature review, questionnaire survey, structured interview, and case study. Comprehensive literature review has been undertaken to gather the information about the knowledge of construction cost estimate and both preliminary and detailed estimates. Nineteen hypotheses have been proposed from the literature review and previous researches to construct the theoretical model for qualitative model (detailed). The quantitative model (preliminary) was also proposed depending on the literature review and previous researches; so both the first and second objectives were achieved and the first and second questions were answered. The field survey was conducted through a questionnaire, which was reliable and valid based on statistical methods. The data from field survey for 79 factors of scales and from cost form were used to test both qualitative and quantitative models of this study. Then, the second objective was confirmed and the third question was answered. The models development were done by the structured interview from the point of views of interviewees. Therefore, the fourth question for this study was answered. In addition, the case study was undertaken to practice both preliminary and detailed models. Consequently, the fifth question for this study was answered. One of the conclusions reveals that the quantitative model can measure the qualitative model’s output perfectly. Further, one of recommendations is recommended that the firms should enhance the knowledge of cost estimate through several trainings for their estimators.