Murat Gunduz

An early cost estimation model for hydroelectric power plant projects using neural networks and multiple regression analysis

AbstractEnergy is increasingly becoming more important in todays world, whereas energy sources are drastically decreasing. One of the most valuable energy sources is hydro energy. Because of limited energy sources and excessive energy usage, cost of energy is rising. Among the electricity generation units, hydroelectric power plants are very important, since they are renewable energy sources and they have no fuel cost. To decide whether a hydroelectric power plant investment is feasible or not, project cost and amount of electricity generation of the investment should be precisely estimated. In this paper, fifty four hydroelectric power plant projects are analysed by using multiple regression and artificial neural network tools. As a result, two cost estimation models have been developed to estimate the hydroelectric power plant project cost in early stages of the project.

A 10-step safety management framework for construction small and medium-sized enterprises

It is of great importance to develop an occupational health and safety management system (OHS MS) to form a systemized approach to improve health and safety. It is a known fact that thousands of accidents and injuries occur in the construction industry. Most of these accidents occur in small and medium-sized enterprises (SMEs). This article provides a 10-step user-friendly OHS MS for the construction industry. A quantitative OHS MS indexing method is also introduced in the article. The practical application of the system to real SMEs and its promising results are also presented.

Analysis of project success factors in construction industry

AbstractA great emphasis has taken place to identify and analyse the factors that have been af- fecting the success and the failure of construction projects in recent decades. As a project-based industry, construction has heavily invested in such research. Moreover, the construction industry suffers the most to meet deadlines and budgets limits. The objective of this paper is to identify the critical success factors in construction industry. The study focused on Middle East region. In order to achieve this objective, 25 project success factors were identified by reviewing related literature. The factors were assessed for their impact and contribution to the actual performance of the project on three criteria: schedule, cost, and quality. Then a questionnaire was developed and sent to dif- ferent experts in the construction industry. The collected data of 111 responses was then analysed statistically by using different tools such as: importance index, Spearmans rank correlation factor and T-test. As a res...

Assessing the risk perception of cost overrun through importance rating

Cost overrun in construction projects is a common issue affecting project performance. After a review of the literature, a list of 39 cost overrun attributes were gathered and presented in a survey. The survey was distributed online to construction professionals. 101 complete responses were received and analyzed by importance index, frequency index, cost index, frequency adjusted cost index, Spearman’s rank correlation, student’s t-test, risk assessment and factor analysis. The results of the survey revealed that the main causes of cost overrun in construction industry include inaccurate cost estimation, improper planning and scheduling, unrealistic contract duration and requirements, frequent changes to the scope of work, frequent design changes, inadequate labor/skill availability, inflation on costs of machinery, labor, material and transportation.

A design reuse technology to increase productivity through automated corporate memory system

Increasing competitiveness in engineering industry pressurizes companies to improve productivity of every single element in processes. As a result of this pressure, increasing productivity of design staff and design systems is systematically investigated by industry professionals and researchers. Design reuse appears as an effective approach to increase productivity levels. It has been already used personally by designers consciously or subconsciously. This paper proposes a computer-based design reuse methodology developed with the purpose of efficient corporate memory usage. The paper focused on steel construction infrastructure design process; however, its approach can be easily implemented in different engineering design processes.

Analysis of change orders in Qatari construction projects

Change orders affect the performance of construction projects and may induce significant cost overruns. The paper identifies the main causes/factors that lead to change orders in Qatari construction projects. It also quantifies the cost overrun impact of these change orders in Qatari construction projects. A total of 1122 change orders were collected from 22 Qatari residential and commercial construction projects. The collected data was analyzed using statistical methods such as Pearson correlation and analysis of variance (ANOVA). The analysis results were used to quantify the change order impacts on cost overruns in Qatari construction projects. Regression analysis models were also developed to predict change order cost overruns with respect to project size/contract value. Finally, recommendations were developed to address change order impacts on cost overruns in the Qatari construction industry.

Assessment of abnormally low tenders: a multinomial logistic regression approach

AbstractThis study was performed in order to reveal factors affecting abnormally low tenders (ALTs) and to minimize negative effects of them. A thorough literature review was carried out to observe past research about the reasons of and possible solutions to ALTs. A questionnaire was prepared and submitted to construction professionals to capture negative impacts of ALTs based on the interviews with experts and past literature. 430 companies responded to the questionnaire. The data analysis was carried out by the multinomial logistic regression statistical tool. Having quality control systems and restricted procedure with prequalification procurement systems were main significant factors to reduce ALTs. Based on all significant factors, recommendations were made to construction professionals and companies to reduce adverse effects of ALTs.