This study aims at identifying the main factors affecting design quality, identifying the main fa... more This study aims at identifying the main factors affecting design quality, identifying the main factors affecting material waste and addressing the relationship between design quality and waste on construction sites in residential building projects in Palestine. To identify the main factors of deign quality and material waste, a questionnaire survey is conducted. Fifteen (15) factors of design quality and 15 factors of material waste are identified from literature review and feedback from local experts. A questionnaire is designed to include these factors. Targeted population included contractors and consultants who have experience in residential projects. Forty five contractors and 35 consultants rank the identified factors according to their importance. The study reveals that the top factors of design quality are: lack of staff experience, inadequate time given for design, payments delay for design services, owners award bids for lowest price designer and copying and modifying from previous designs. It also indicates the significant factors of material waste, they include: design mistakes, late design changes, rework, lack of labor experience and purchasing materials not complying with specifications. Based on data collected from 33 building projects, a predictive model is established. The model indicates a good relation between material waste and design quality.
The study aims at identifying the factors affecting time overrun in public construction projects ... more The study aims at identifying the factors affecting time overrun in public construction projects Saudi Arabia from consultants’ viewpoint. To do so, 70 consultants working in public construction completed a structured questionnaire survey and the factors were ranked according to their levels of severity, frequency, and importance. 34 factors were identified through interview with some local construction experts and deep literature review. The analysis of the identified 34 factors indicates that the top five important factors affecting time overrun in public construction projects are: improper planning, poor labor productivity, additional works, rework, and lack of contractor experience. The results also indicate that the top five severe factors affecting time overrun in public construction projects in Saudi Arabia are: bid award for lowest price, poor labor productivity, improper planning, additional work, and lack of contractor experience. While the top five frequent factors are: rework, improper planning, changes in material types and specifications during construction, poor contract management, and poor resource management.
Engineering, Technology & Applied Science Research
The purpose of this study is to identify and rank the factors influencing the bid/no-bid decision... more The purpose of this study is to identify and rank the factors influencing the bid/no-bid decision according to their relative importance from the perspective of the contractors in the West Bank in Palestine. To achieve the study objectives, a questionnaire survey was conducted. The survey covered a randomly selected sample of 64 contractors involved in the construction industry in the West Bank. The questionnaire’s structure is based on the related literature, the pilot study, and the feedback from local experts in the construction industry. A total of 32 factors that might influence the bid/no-bid decision were identified and considered. Then, the targeted population was asked to rank these factors according to their relative importance. The results indicate that the top five factors affecting a contractor’s decision to bid or not include the financial stability of the client, the identity and reputation of the client in the industry, the promptness of the client in the payment pro...
International Journal of ADVANCED AND APPLIED SCIENCES
This study is conducted to recognize the major delay factors, the major construction productivity... more This study is conducted to recognize the major delay factors, the major construction productivity factors, and to establish the relationship between productivity and delay in construction projects in Saudi Arabia. A questionnaire survey is performed to achieve study objectives. Fourteen-time overrun factors and 13 construction productivity factors are listed in a questionnaire form. Fifty contractors consultants are asked to rank the identified factors according to their importance. The study also addresses the relationship between labor productivity and time overrun based on data collected from 34 building projects implemented in Saudi Arabia. Results conclude that the top factors affecting delay in construction projects are: poor labor productivity, poor coordination between construction parties, lack of adequate manpower, bid award for lowest price, and mistakes in design. It also indicates that the major labor productivity factors are: payments delay, lack of labor experience, f...
This study investigates the statistical relationship between actual and estimated cost of road co... more This study investigates the statistical relationship between actual and estimated cost of road construction activities. It is based on a sample of 100 road construction projects awarded in the West Bank in Palestine over the years 2004- 2008. Based on this data, regression models were developed. The investigated construction activities in this study are earthworks, base works, asphalt works and furniture works. The findings reveal that the average cost deviation in the investigated activities is as follows: earthworks =-15.7%, base works = 12.9%, asphalt works = 18.5 % and furniture works = 36.4%. The relationship between cost divergence of each investigated activity and physical project characteristics (i.e. project size, terrain condition, ground condition and soil quality) is discussed.
This study aims at developing regression models to predict the total construction cost of a road ... more This study aims at developing regression models to predict the total construction cost of a road project in the early phases. The models were developed based on 52 sets of data collected in Saudi Arabia. The projects were implemented during 2011. The procedure used resulted in the formulation of 5 regression models; 2 of them include bid quantities of the major construction activities as independent variables and 3 include road length and road width as independent variables. The coefficient of determination (r2) of the developed models is ranging from 0.65 to 0.97. This indicates that the relationship between the dependent and independent variables of the developed models is good and the predicted values from a forecast model fit with the real-life data. The value of the Mean Absolute Percentage Error (MAPE) of the developed regression models is tested. It is ranging from 17% to 42%. The results compare favorably with past researches which have shown that the estimate accuracy in th...
The study aims at identifying the factors affecting labor productivity in public construction pro... more The study aims at identifying the factors affecting labor productivity in public construction projects in Saudi Arabia from contractors’ viewpoint. To do so, 41 contractors working in public construction completed a structured questionnaire survey and the factors were ranked according to their impact level. 32 factors were identified through literature review. These factors were grouped into five groups: labor, managerial, materials and equipments, project, and financial. The analysis of the identified 32 factors indicates that the top ten important factors negatively affecting labor productivity in public construction projects are: lack of labor experience, poor communication and coordination between construction parties, bad relations between labors and management team, payments delay by owner, misuse of time schedule, rework, labor’s low wage, financial conditions of contractor, poor site management, and frequent change orders. Index Term-Labors, productivity, contractors, public...
The main objective of this paper is to identify the factors that have the potential to cause cont... more The main objective of this paper is to identify the factors that have the potential to cause contractor's business failure in the West Bank in Palestine and to determine their impact level from contractor's viewpoint. A questionnaire survey of 84 contractors was performed. 44 factors were identified through literature review and were listed under the following three groups: financial, managerial, and external. The identified factors are ranked according to their importance as assessed by the respondents. The findings reveal that the top five affecting factors are: fluctuation in construction material cost, delay in collecting dibs from clients, lack of experience in contracts, low margin of profit due to competition, and closure and limitation of movement between West Bank areas.
Introduction This study is conducted to establish the effect of design quality on project delay i... more Introduction This study is conducted to establish the effect of design quality on project delay in building projects. It aims at: 1) investigating the major factors of design quality, 2) identifying the main delay factors in building projects, 2) establishing the relationship between design quality and delay in building projects. To achieve these objectives, a questionnaire survey is performed. Seventeen (17) factors that might affect design quality, and 15 delay factors are listed in a questionnaire form. Sixty (60) contractors and 40 consultants are asked to identify the severity of the identified factors. Results indicate that the top factors affecting design quality are: delay in payments by client for design services, staff allocation for many projects at the same time, copying and modifying from previous work to minimize time and cost, tight design schedule, lack of designer knowledge with techniques and materials available in the market. The study also concludes that the top ...
The aim of compiling this book has been to give a working knowledge of the important researches o... more The aim of compiling this book has been to give a working knowledge of the important researches of road construction management, including the cost overrun, time overrun, labor productivity, change orders, reworks, and cost estimating to all engineering students, professors, professionals, and researchers in a systematic way. This book is based on a series of researches undertaken and personal work experience of the author. The book is written in a clear and easy-to-read style.
This study is conducted to identify the cost overrun causes in road construction projects in the ... more This study is conducted to identify the cost overrun causes in road construction projects in the West Bank in Palestine from consultants’ view. A questionnaire survey of 40 consultants from was performed. The survey included 51 suggested factors through literature review. The factors are ranked according to the degree of importance as assessed by the respondents. The findings reveal that the top five affecting factors are: materials price fluctuation, insufficient time for estimate, experience in contracts, size of contract, and incomplete drawings.
This study was motivated by long term observations of the construction industry in the Northern r... more This study was motivated by long term observations of the construction industry in the Northern region of the Kingdom of Saudi Arabia (KSA). The observations showed that the construction waste is becoming a serious environmental, economical and safety issue that affects the suburbs of the KSA. The study utilizes Likert scaled responses through a two-part questionnaire distributed to 42 contractors located in the Northern region of KSA. The first part of the questionnaire aims at identifying causes of material waste in building construction projects from the contractors' viewpoint. The second part seeks to rank the considered materials according to their level of importance from the contractors' viewpoint. The collected data was analyzed through Minitab statistical software. It was found that the most significant factors causing construction waste are: (1) inaccuracy in quantity surveys leading to over- ordering or under-ordering; (2) the selection of low quality products; (3...
The objectives of this study included: (1) identifying the factors affecting construction labor p... more The objectives of this study included: (1) identifying the factors affecting construction labor productivity, (2) identifying the causes of rework in building projects, (3) addressing the relationship between labor productivity and rework using regression analysis based on data collected from building projects implemented in Palestine. The following steps were used in this study: (1) Questionnaire survey – stage 1: a questionnaire survey was carried out to identify the main factors affecting labor productivity and the main causes of rework on construction sites, (2) Questionnaire survey – stage 2: after identifying the significant causes of rework using factor analysis, a questionnaire survey was conducted to address the impact of these significant causes on labor productivity, (3) Prediction models: Data collected from 40 building construction projects were used to establish the regression models that describe the relation between rework and labor productivity on construction sites...
The Palestinian construction sector is one of the key economic sectors and is the main force moti... more The Palestinian construction sector is one of the key economic sectors and is the main force motivating the national economy. However, it is complex and affected by many constraints and obstacles that influence its outcomes. Therefore, this research was conducted with the aims to survey the construction contracting problems in Palestine from the different local contract stakeholders’ points of view; namely: contractors, owners, consultants and donor countries and institutions. 73 problems were collected and considered in this research and grouped in eleven main groups; namely, financial, political, administrative problems and problems related to the tender documents (contracts, drawings), specification and material adaptation (quality), contract parties themselves, sector environment, natural environment, arbitration and dispute solving, technology use and career ethics. A questionnaire was administered to evaluate the importance of the construction related problems. 310 questionnai...
This study aims at identifying the main factors affecting design quality, identifying the main fa... more This study aims at identifying the main factors affecting design quality, identifying the main factors affecting material waste and addressing the relationship between design quality and waste on construction sites in residential building projects in Palestine. To identify the main factors of deign quality and material waste, a questionnaire survey is conducted. Fifteen (15) factors of design quality and 15 factors of material waste are identified from literature review and feedback from local experts. A questionnaire is designed to include these factors. Targeted population included contractors and consultants who have experience in residential projects. Forty five contractors and 35 consultants rank the identified factors according to their importance. The study reveals that the top factors of design quality are: lack of staff experience, inadequate time given for design, payments delay for design services, owners award bids for lowest price designer and copying and modifying from previous designs. It also indicates the significant factors of material waste, they include: design mistakes, late design changes, rework, lack of labor experience and purchasing materials not complying with specifications. Based on data collected from 33 building projects, a predictive model is established. The model indicates a good relation between material waste and design quality.
The study aims at identifying the factors affecting time overrun in public construction projects ... more The study aims at identifying the factors affecting time overrun in public construction projects Saudi Arabia from consultants’ viewpoint. To do so, 70 consultants working in public construction completed a structured questionnaire survey and the factors were ranked according to their levels of severity, frequency, and importance. 34 factors were identified through interview with some local construction experts and deep literature review. The analysis of the identified 34 factors indicates that the top five important factors affecting time overrun in public construction projects are: improper planning, poor labor productivity, additional works, rework, and lack of contractor experience. The results also indicate that the top five severe factors affecting time overrun in public construction projects in Saudi Arabia are: bid award for lowest price, poor labor productivity, improper planning, additional work, and lack of contractor experience. While the top five frequent factors are: rework, improper planning, changes in material types and specifications during construction, poor contract management, and poor resource management.
Engineering, Technology & Applied Science Research
The purpose of this study is to identify and rank the factors influencing the bid/no-bid decision... more The purpose of this study is to identify and rank the factors influencing the bid/no-bid decision according to their relative importance from the perspective of the contractors in the West Bank in Palestine. To achieve the study objectives, a questionnaire survey was conducted. The survey covered a randomly selected sample of 64 contractors involved in the construction industry in the West Bank. The questionnaire’s structure is based on the related literature, the pilot study, and the feedback from local experts in the construction industry. A total of 32 factors that might influence the bid/no-bid decision were identified and considered. Then, the targeted population was asked to rank these factors according to their relative importance. The results indicate that the top five factors affecting a contractor’s decision to bid or not include the financial stability of the client, the identity and reputation of the client in the industry, the promptness of the client in the payment pro...
International Journal of ADVANCED AND APPLIED SCIENCES
This study is conducted to recognize the major delay factors, the major construction productivity... more This study is conducted to recognize the major delay factors, the major construction productivity factors, and to establish the relationship between productivity and delay in construction projects in Saudi Arabia. A questionnaire survey is performed to achieve study objectives. Fourteen-time overrun factors and 13 construction productivity factors are listed in a questionnaire form. Fifty contractors consultants are asked to rank the identified factors according to their importance. The study also addresses the relationship between labor productivity and time overrun based on data collected from 34 building projects implemented in Saudi Arabia. Results conclude that the top factors affecting delay in construction projects are: poor labor productivity, poor coordination between construction parties, lack of adequate manpower, bid award for lowest price, and mistakes in design. It also indicates that the major labor productivity factors are: payments delay, lack of labor experience, f...
This study investigates the statistical relationship between actual and estimated cost of road co... more This study investigates the statistical relationship between actual and estimated cost of road construction activities. It is based on a sample of 100 road construction projects awarded in the West Bank in Palestine over the years 2004- 2008. Based on this data, regression models were developed. The investigated construction activities in this study are earthworks, base works, asphalt works and furniture works. The findings reveal that the average cost deviation in the investigated activities is as follows: earthworks =-15.7%, base works = 12.9%, asphalt works = 18.5 % and furniture works = 36.4%. The relationship between cost divergence of each investigated activity and physical project characteristics (i.e. project size, terrain condition, ground condition and soil quality) is discussed.
This study aims at developing regression models to predict the total construction cost of a road ... more This study aims at developing regression models to predict the total construction cost of a road project in the early phases. The models were developed based on 52 sets of data collected in Saudi Arabia. The projects were implemented during 2011. The procedure used resulted in the formulation of 5 regression models; 2 of them include bid quantities of the major construction activities as independent variables and 3 include road length and road width as independent variables. The coefficient of determination (r2) of the developed models is ranging from 0.65 to 0.97. This indicates that the relationship between the dependent and independent variables of the developed models is good and the predicted values from a forecast model fit with the real-life data. The value of the Mean Absolute Percentage Error (MAPE) of the developed regression models is tested. It is ranging from 17% to 42%. The results compare favorably with past researches which have shown that the estimate accuracy in th...
The study aims at identifying the factors affecting labor productivity in public construction pro... more The study aims at identifying the factors affecting labor productivity in public construction projects in Saudi Arabia from contractors’ viewpoint. To do so, 41 contractors working in public construction completed a structured questionnaire survey and the factors were ranked according to their impact level. 32 factors were identified through literature review. These factors were grouped into five groups: labor, managerial, materials and equipments, project, and financial. The analysis of the identified 32 factors indicates that the top ten important factors negatively affecting labor productivity in public construction projects are: lack of labor experience, poor communication and coordination between construction parties, bad relations between labors and management team, payments delay by owner, misuse of time schedule, rework, labor’s low wage, financial conditions of contractor, poor site management, and frequent change orders. Index Term-Labors, productivity, contractors, public...
The main objective of this paper is to identify the factors that have the potential to cause cont... more The main objective of this paper is to identify the factors that have the potential to cause contractor's business failure in the West Bank in Palestine and to determine their impact level from contractor's viewpoint. A questionnaire survey of 84 contractors was performed. 44 factors were identified through literature review and were listed under the following three groups: financial, managerial, and external. The identified factors are ranked according to their importance as assessed by the respondents. The findings reveal that the top five affecting factors are: fluctuation in construction material cost, delay in collecting dibs from clients, lack of experience in contracts, low margin of profit due to competition, and closure and limitation of movement between West Bank areas.
Introduction This study is conducted to establish the effect of design quality on project delay i... more Introduction This study is conducted to establish the effect of design quality on project delay in building projects. It aims at: 1) investigating the major factors of design quality, 2) identifying the main delay factors in building projects, 2) establishing the relationship between design quality and delay in building projects. To achieve these objectives, a questionnaire survey is performed. Seventeen (17) factors that might affect design quality, and 15 delay factors are listed in a questionnaire form. Sixty (60) contractors and 40 consultants are asked to identify the severity of the identified factors. Results indicate that the top factors affecting design quality are: delay in payments by client for design services, staff allocation for many projects at the same time, copying and modifying from previous work to minimize time and cost, tight design schedule, lack of designer knowledge with techniques and materials available in the market. The study also concludes that the top ...
The aim of compiling this book has been to give a working knowledge of the important researches o... more The aim of compiling this book has been to give a working knowledge of the important researches of road construction management, including the cost overrun, time overrun, labor productivity, change orders, reworks, and cost estimating to all engineering students, professors, professionals, and researchers in a systematic way. This book is based on a series of researches undertaken and personal work experience of the author. The book is written in a clear and easy-to-read style.
This study is conducted to identify the cost overrun causes in road construction projects in the ... more This study is conducted to identify the cost overrun causes in road construction projects in the West Bank in Palestine from consultants’ view. A questionnaire survey of 40 consultants from was performed. The survey included 51 suggested factors through literature review. The factors are ranked according to the degree of importance as assessed by the respondents. The findings reveal that the top five affecting factors are: materials price fluctuation, insufficient time for estimate, experience in contracts, size of contract, and incomplete drawings.
This study was motivated by long term observations of the construction industry in the Northern r... more This study was motivated by long term observations of the construction industry in the Northern region of the Kingdom of Saudi Arabia (KSA). The observations showed that the construction waste is becoming a serious environmental, economical and safety issue that affects the suburbs of the KSA. The study utilizes Likert scaled responses through a two-part questionnaire distributed to 42 contractors located in the Northern region of KSA. The first part of the questionnaire aims at identifying causes of material waste in building construction projects from the contractors' viewpoint. The second part seeks to rank the considered materials according to their level of importance from the contractors' viewpoint. The collected data was analyzed through Minitab statistical software. It was found that the most significant factors causing construction waste are: (1) inaccuracy in quantity surveys leading to over- ordering or under-ordering; (2) the selection of low quality products; (3...
The objectives of this study included: (1) identifying the factors affecting construction labor p... more The objectives of this study included: (1) identifying the factors affecting construction labor productivity, (2) identifying the causes of rework in building projects, (3) addressing the relationship between labor productivity and rework using regression analysis based on data collected from building projects implemented in Palestine. The following steps were used in this study: (1) Questionnaire survey – stage 1: a questionnaire survey was carried out to identify the main factors affecting labor productivity and the main causes of rework on construction sites, (2) Questionnaire survey – stage 2: after identifying the significant causes of rework using factor analysis, a questionnaire survey was conducted to address the impact of these significant causes on labor productivity, (3) Prediction models: Data collected from 40 building construction projects were used to establish the regression models that describe the relation between rework and labor productivity on construction sites...
The Palestinian construction sector is one of the key economic sectors and is the main force moti... more The Palestinian construction sector is one of the key economic sectors and is the main force motivating the national economy. However, it is complex and affected by many constraints and obstacles that influence its outcomes. Therefore, this research was conducted with the aims to survey the construction contracting problems in Palestine from the different local contract stakeholders’ points of view; namely: contractors, owners, consultants and donor countries and institutions. 73 problems were collected and considered in this research and grouped in eleven main groups; namely, financial, political, administrative problems and problems related to the tender documents (contracts, drawings), specification and material adaptation (quality), contract parties themselves, sector environment, natural environment, arbitration and dispute solving, technology use and career ethics. A questionnaire was administered to evaluate the importance of the construction related problems. 310 questionnai...
Uploads
Papers by Ibrahim Mahamid