## Keywords

Delay causes; Delay groups; Road construction projects; Questionnaires; Relative Importance Index (RII); Egypt

## 1. Introduction

Time is money; delay in a certain construction project affects time and thus money, which is the lifeblood of any economy. The timely completion of highway construction projects is considered one of the most important factors referring to the project success, as well as the quality and the safety. All around the world many construction projects face one of the biggest construction problems which is the delay, delays differ from a country to another, from a construction project to another and from construction type or cost to another due to every project circumstances Sullivan and Harris [55]. Delay affects every party in the construction project in a different way as for the owner or the contractor it affects differently but not the same as the consultant who is considered the least affected party of all. Many small and large size contractors in recent years have voiced their concerns over the difficulty to overcome delay problems, and the main reason is because the contractors have no ability to identify the important causes of delay occurring during the construction process. Ranking the importance of delay variables by project managers enables identification of the most important variables and assists them to seek best alternative solutions, Alwi and Hampson [8]. Effective project time management is highly dependent on the contractor, and can be adversely affected in a number of ways. Contractors must ensure that the building is constructed within the contractual completion date, or risk the imposition of financial penalties. If the principle or their agents are the cause of the delay however, the completion date may be extended to compensate the contractor. The principal and their agent must therefore ensure that they provide the contractor with information in a timely manner, to avoid causing delays. Contract conditions may also contain provisions for the contractor to be awarded extensions of time (EOT) for other types of specified delays, such as inclement weather, Finnie [19]. Project value was found to have a negative correlation with time loss due to demotivation, indicating that as project size increases time loss decreases, Ng et al. [45]. Some studies conclude that groups and factors causing delays are country, location and project specific and that there are no root causes that can be generalized, Ramanathan et al. [51]. Other studies defined the root causes of delay as situations or conditions that violated the fundamental principles and were defined in sufficient detail that allowed corrective action to be taken, Ellis and Thomas [32]. So this research studies the concept of having root delay causes affecting delay or not and ranks the causes of delay in road construction projects in Egypt The following sections present literature review, research methodology, results with discussions and conclusions with recommendations.

## 2. Literature review

Different definitions of delay were found, and the delay is the most common, costly, complex and risky problem encountered in construction projects, Ahmed et al. [3]. The delay is the time overrun either beyond completion date specified in a contract, or beyond the date that the parties agreed upon for delivery of a project, Assaf and Al-Hejji [11].

Different numbers of causes were found in each study with different important causes and ways of ranking the causes. Fig. 1 presents the classification of the causes in each research on the type of construction.

 Figure 1. Classification of number of causes gathered from the literature review.

The variation in the number of delay causes for each type of construction as in general type of construction, number of delay causes studied in different research’s ranging from 113 delay cause in Malaysia to 7 delay causes in Hongkong. General construction type projects is studied in 16 various countries all over the world showing that a country like Malaysia is studied in two different researchs with two different numbers of delay causes (113) and (28). The majority of the researchs studied the causes of delay affecting general construction projects followed by research’s studying causes of delay affecting building construction projects in different four countries, then research’s studying pipeline construction projects in two different countries and finally only one research studied the causes of delay affecting the road construction project in Palestine. Causes of delay in road construction projects are taken to these studies purpose to widen the research’s studying the road projects since the timely completion of highway construction projects is a national priority. Identifying the root causes and recognizing fundamental principles is a starting point.

Menesi [44] classified the types of delay into two different types according to liability as follows: (1) Excusable delays which are divided into (a) Compensable (Owner) and (b) Non-Compensable; (2) Inexcusable delays; and Concurrent delays. Kraiem and Diekmann [36] mentioned time allowed for construction project performance is usually an important consideration for both the project owner and the project contractor. Yet, it is typical for construction projects to be delayed. Delays may be caused by the owner (compensable delay), by the contractor (nonexcusable delay), by acts of god, or a third party (excusable delay), or several different kinds of delays may happen concurrently.

Ogunlana et al. [48] identified 26 delay causes affecting construction industry in a fast-growing economy in Thailand categorized them into 6 groups, and data were collected by visiting sites and mailing to 17 contractors, 18 consultants and design firms and one project owner. 8 contractors and 6 consultants gave approval of which only 12 projects were selected for visits. Interviews were conducted on site using structured and unstructured interview schedules. A total of 30 persons, representing 2.5 persons per project, were interviewed. The results of the survey have been compared with studies from other developing economies. The results of the study support the view that construction industry problems in developing economies can be nested in three layers: (a) problems of shortages or inadequacies in industry infrastructure (mainly supply of resources); (b) problems caused by clients and consultants and (c) problems caused by contractor incompetence/inadequacies.

Greenwood et al. [23] declared that hospital projects are particularly susceptible to delays, some of which appear to be common to the construction of large hospitals wherever they are built. In a number of surveys of construction professionals, one of the most influential causes of delay on large public projects has been found to be administrative reasons, and aimed to use these studies as a basis for exploring the impact of administrative delays on the construction of hospitals.

Odeh and Battaineh [47] identified 28 delay causes affecting construction projects with traditional type of contracts in Jordan; first, a survey questionnaire was developed to assess the perceptions of contractors and consultants of the relative importance of construction delay causes. Second, the questionnaire was distributed to a random sample of contractors and consultants working on large projects in Jordan. The Spearman’s rank correlation coefficient was then used to test association between the contractors and consultants ranking. The study revealed that Owner interference, inadequate contractor experience, financing and payments, labor productivity, slow decision making, improper planning, and subcontractors are among the ten most important factors, according to contractors, and labor productivity was the most important delay factor. Inadequate contractor experience was the most important delay factor to consultants.

Aibinu and Odeyinka [4] assessed causes of delays by focusing on actions and inactions of project participants and external factors. The study analyzed quantitative data from completed building projects to assess the extent of delays, and data obtained from a questionnaire survey of construction managers to assess the extent to which 44 identified factors contributed to overall delays on a typical project they have been involved with. The findings showed that the factors could be prioritized. However, Pareto analysis revealed that 88% of the factors (representing 39 highest priority factors) were responsible for 90% of the overall delays. There is no discernable difference among the different delay factors and none really stands out as contributing to a large percentage of the problem. A one-sample t test further confirmed that most of the factors are important contributors to delays.

Abdul-Rahman et al. [2] described the importance of applying proper management in dealing with delays in construction for a growing economy. The main objective of this paper was to identify the management tools that were practiced in the local construction industry in mitigating delay. It also aims to identify the main factors that lead to project delays and to suggest recommendations on how to overcome or mitigate effects of the problem. Then they highlighted the importance of having more experienced and capable construction managers as well as skilled laborers to enable the industry to develop at a faster rate either nationally or internationally.

Lo et al. [39] aimed for gathering the perceptions of civil construction practitioners on how significant are the causes of delay. The extent of the differences in perception among the different respondent groups was also examined using the rank agreement factor (RAF), percentage agreement (PA), and percentage disagreement (PD). The differences in the perceptions of the respondents on the significance of delays and the actual causes of delays for the six projects studied were also examined. A strong consensus was found between the client and consultant groups on the significance of the various causes of delay (PA = 74%) and the effectiveness of mitigation measures (PA = 67%) compared with the other pairs of groups. The consultant and contractor groups held extremely different perceptions regarding the significance of various delay causes (RAF = 4.9 and PD = 32%) and the effectiveness of corresponding mitigation measures (RAF = 6.2 and PD = 47%). It is believed that the findings can provide much more insight for the construction practitioners as well as the researchers and thus help to improve the productivity and overall performance of civil engineering projects in Hong Kong.

Hegab and Smith [29] defined delay in microtunneling as the nonworking time of a microtunneling project due to any reason other than scheduled stops. There were more reasons for delay such as mechanical failure of system components, leakage of hydraulic hoses, blockage of slurry pipes, and waiting time for excavated materials hauling equipment. Delay data were collected from 35 microtunneling projects. Collected delay data were delay duration, delay reason, time, and location from the start to the stopping point. Five categories of delay causes were used in the analysis. Prediction of delay time will enhance the estimation accuracy of microtunneling project duration. A predictive model using a probabilistic approach was selected to represent the delay time. Based on data characteristics, a Weibull distribution was determined to best represent the overall delay duration in microtunneling projects. Using “regression with life data,” expected overall delay in a microtunneling project could be predicted as a function of driven length. The model will help contractors to estimate total project time with reasonable accuracy. Knowing the anticipated delay time will allow contractors to have a point of comparison for actual performance.

Le-Hoai et al. [38] identified 21 delay causes of large construction projects in Vietnam, listed in six respective groups through field survey methodology and literature reviews, a pilot questionnaire was prepared and 6 experts in Vietnamese construction industry (VCI) were involved to critically review the design and structure of the questionnaire then it was ready to survey. A total of 285 questionnaires are sent to construction professionals, and 87 full responses are obtained showing a response rate of 30.5%. The data are processed through three indices: frequency index, Severity index, and importance index and then to analyze the agreement between each two parties in respect to the causes of delay was measured using Spearman’s rank correlation coefficients. From the results it is noted that poor site management and supervision, poor project management assistance, financial difficulties of owner, financial difficulties of contractor, design changes are five most frequent, severe and important causes.

Toor and Ogunlana [57] developed questionnaire surveys and interviews that were conducted on a major construction project in Thailand to explore the most significant problems causing construction delays. Factors related to designers, contractors and consultants were rated among the top problems. Issues such as lack of resources, poor contractor management, shortage of labor, design delays, planning and scheduling deficiencies, changed orders and contractors’ financial difficulties were also highlighted during the interviews. Notably, problems such as ‘multicultural and multilingual environment causing ineffective communication’, ‘large number of participants of project’ and ‘involvement of several foreign designers and contractors’ were rated among the bottom 10 problems in the 75‐item problem inventory.

Sweis et al. [56] identified and classified the causes of construction delays in residential projects according to Drewin’s Open Conversion System. The most common causes were evaluated by using both, the data collected in a survey conducted to residential projects consultant engineers, contractors, and owners, and interviews with senior professionals in the field. Most correspondents agreed that, financial difficulties faced by the contractor and too many change orders by the owner are the leading causes of construction delay. Severe weather conditions and changes in government regulations and laws ranked among the least important causes.

Hegazy and Menesi [30] introduced improvements to a computerized schedule analysis model so that it will produce accurate and repeatable results. The model considered multiple baseline updates due to changes in the durations of the activities and the logical relationships among them, as well as the impact of resource overallocation. The model used a daily window size in order to consider all fluctuations in the critical paths and uses a legible representation of progress information to accurately apportion delays and accelerations among project parties. A simple case study has been implemented to demonstrate the accuracy and usefulness of the proposed delay analysis model.

Kaliba et al. [34] aimed to identify causes and effects of cost escalation and schedule delays in road construction projects. Using a detailed literature review, structured interviews and questionnaire surveys, the results of the study confirmed the prevalence of cost escalation and schedule delays in road construction projects in Zambia. The study established that bad or inclement weather due to heavy rains and floods, scope changes, environmental protection and mitigation costs, schedule delay, strikes, technical challenges, inflation and local government pressures were the major causes of cost escalation in Zambia’s road construction projects.

Al-Kharashi and Skitmore [6] reported A new survey in Kingdom of Saudi Arabia that uses all the variables from the previous work and measures for both current degree of effect on delays and the extent to which each can be practically improved. These are contained in seven groupings: client, contractor, consultant, materials, labor, contract and relationship‐related causes. The survey covers a sample of 86 clients, contractors and consultants working in the Saudi construction industry. The analysis found that the most influencing current cause of delay is the lack of qualified and experienced personnel attributed to the considerable amount of large, innovative, construction projects and associated current undersupply of manpower in the industry.

Yang and Wei [61] identified 35 delay causes, 15 causes in the planning phase and 20 causes in the design phase for construction projects in Taiwan by sending a structured questionnaire to engineers at the A/E companies for public construction projects in Taiwan resulting in 95 valid responses identifying the delay causes. This study used the Likert scale in questionnaire design to plot the importance-frequency matrix and ranked the factors by the importance and frequency of delays using the Relative Importance Index then calculated the severity index. Analytical results reveal that changes in clients requirement are the main causes of delay in both planning and design phases.

Soliman [54] identified 29 delay causes affecting construction projects in Kuwait through refining previous researches, categorized them into six groups then subjected to a questionnaire survey including 30 respondents made up of 9 contractors, 5 owners and 16 consultants. Data collected were analyzed by importance index and then an agreement analysis was calculated using the Spearman’s rank correlation coefficient to show the degree of agreement between the rankings of any two parties. The study revealed that the financial and design related causes of delays are the most important and frequent causes. The top five delay causes that were resulted from contractors category were: delay of document submission from consultant, delaying of payments from owner, conflict between contractor and consultant, in-appropriate owner representative’s management style and owner financial problems, While the five top delay causes from consultants category are: owner financial problems, contractor financial problems, inefficient management capability of contractor staff, conflict between contractor and consultant, and no planning before project start.

Orangi et al. [49] identified 15 delay causes affecting pipeline projects in Victoria-based pipeline in Australia. the research methods include detailed literature review, targeted interviews with several project managers, and case-study based knowledge mining from some pipeline projects. A set of root causes for delays in pipeline infrastructure works have been identified such as design changes, design errors, design submission delays, lack of communication between designers and contractors, lack of communication between client and project team, customer/end-user related issues, inadequate geotechnical investigations, issues regarding client approvals, issues regarding permissions, adverse weather conditions, delays by material suppliers, poor site management practices, planning and scheduling errors, construction rework, cultural and heritage management issues and subcontractor issues.

Hasseb et al. [28] identified 37 delay causes affecting construction industry in Pakistan. A survey was conducted through mailed 200 questionnaires that were distributed in government, private and semi government organization out of which 120 were given response and in some organizations interviews were vocally taken by the labors or private firms. The delay factors are assessed by the critical assessment criteria such as mean delay factor range, mode and critical index. The survey results indicated that the majority of delay factors are relevant to client factor which must have strong economical ability and financial arrangement for project, correctly time decision. Most factors related to consultant are due to not understanding the client necessities, not having proper project information, absence of some detail in drawing. And due to contractor most delay factors occur because of deficient in obtaining up-to-date equipments, unwarranted material used in construction. Client must be mentally and financially strong for starting a new project due to which delays can be reduced in projects.

Hamzaha et al. [27] declared that the improvement of delay factors not only limited to technical factors, but also factors in project management perspective both from the aspect of processes involving and the influence of human attitudes, mentality, skills and behavior. With that spirit, study based on the same issue and problems but looking from a different angle had been conducted and delay framework has been proposed. The depth studies as to what extent these factors and variables can positively and negatively affect the construction project are suggested for future study. The reliability and criticality of framework are also required to validate the significance of the framework.

Wambeke et al. [59] examined the similarities and differences in perceptions between craft workers, foremen, and project managers in terms of starting time and task duration variation. The top eight causes of starting time variation and top nine causes of task duration variation were identified. Also quantitatively it was analyzed the underlying structure of the causes of variation using factor analysis. This was done by grouping the 50 individual causes into nine orthogonal factors that represent the underlying structure of the affecting causes.

Mahamid et al. [42] identified 52 delay causes affecting road construction projects in Palestine through a questionnaire survey, categorized them into eight groups. Then subjected to a questionnaire survey including 34 contractors and 30 consultants, owners are not included because the road construction projects are public projects and funded by the government and therefore only one client cannot be studied through a questionnaire. The suggested delay causes in road construction projects are ranked by the measurement of the severity index then the Spearman’s rank correlation is used to measure the degree of correspondence between the two respondents. The survey concluded that the top five severe delay causes from the combined point of view of the contractor and the consultant are political situation, segmentation of the west bank and limited movement between areas, award project to lowest bid price, progress payment delay by owner, and shortage of equipment, approximately 75% of the participating contractors and 70% of the consultants indicated that the average time overrun for the projects they have experienced is between 10% and 30% of the original project duration, and approximately 20% of the contractors and 25% of the consultants indicated 30–50% time overrun compared with the origin specified duration, neither consultants nor contractors indicated any time delay greater than 100% of the original contract duration.

Kazaz et al. [35] examined the causes of time extensions in the Turkish construction industry and levels of their importance together. In total, 34 factors affecting project duration were taken into account. A questionnaire survey, including these factors, was then applied to 71 construction companies in Turkey, and the outcomes were evaluated by means of statistical analyses. According to the results, “design and material changes” was found to be the most predominant factor, followed by “delay of payments” and “cash flow problems”. In terms of importance levels of factor groups, financial factors were found to be the first group, while environmental factors were the least effective group. It should be also noted that managerial causes of time extensions are encountered in developed and developing countries, whereas financial causes are experienced in developing countries only.

Niazai and Gidado [46] identified 83 delay causes affecting construction industry in Afghanistan categorized them into nine groups, through in-depth literature studies questionnaires were developed and sent to 60 carefully selected construction industry stakeholders including: 20 client, 25 contractor, and 15 consultant in Afghanistan. The importance index was used to analyze the data gathered and the agreement between each two parties in respect to the causes of delay was measured using Spearman’s rank correlation coefficients. The findings show that the main critical factors that cause construction delays in Afghanistan are: security, corruption, poor qualification of the contractor’s technical staff, payment delays by clients, and poor site management and supervision by contractor. The respondents reported that contract with less than 12 months highly contributes to delays and the most common time spent for the most delayed projects in Afghanistan is between 1 to 6 months.

Hamzah et al. [26] determined the causes of delay in Malaysian construction industries based on previous worldwide research. The field survey conducted includes the experienced developers, consultants and contractors in Malaysia. 34 causes of the construction delay have been determined and 24 have been selected. The analysis result will be used as the baseline for the next researches to find the causes of delay in the Malaysian construction industry taking place in Malaysian higher learning institutions.

Yang and Kao [60] used Windows-based delay analysis methods for identifying and measuring construction schedule delays. Based on a previous study identifying potential problems in available windows-based delay analysis methods, this study proposes an innovative windows-based delay analysis method, called the effect-based delay analysis method (EDAM). The EDAM performed delay analysis using extracted windows and determined delay impacts by considering the effects of delays on the critical paths. According to its application to hypothetical cases and comparisons with other methods, EDAM is efficient in delay analysis and effective in solving concurrent delays and determining schedule shortened and is a good alternative for schedule delay analysis for construction projects.

Anastasopoulos et al. [9] used data from 1722 highway projects in Indiana, random-parameter statistical models are estimated to study the factors that contribute to the likelihood of encountering a project time delay and its duration. The model estimation results show that the likelihood and duration of project time delays are significantly influenced by factors such as project cost (contract bid amount), project type, planned project duration, and the likelihood of adverse weather.

Rahsid et al. [50] explored the causes of delay in construction projects. Data on the study variables have been collected through structured questionnaire from 37 construction firms located in Pakistan. Various statistical tools such as reliability test, factor analysis and regression have been applied for data analysis and inference. The results of the study reveal that the factors related to contractor, client, consultant, material and equipment have significant impact on delay in construction project whereas labor and general environment factors found to have no effects on delay. The findings of the study provide significant insights to construction industry so that they may formulate strategies in order to avoid delay and its consequences.

Aziz [12] identified relative importance indices and determined the influence ranks of ninety-nine (99) factors causing delay in construction projects in Egypt. It addressed the most significant factors and groups causing delays, especially after Egyptian revolution. The explored factors were classified under the following nine (9) primary classifications: (1) Consultant related delay factors; (2) Contractor related delay factors; (3) Design related delay factors; (4) Equipment related delay factors; (5) External related delay factors; (6) Labor related delay factors; (7) Material related delay factors; (8) Owner related delay factors; and (9) Project related delay factors. To study the effect of participants’ experience on the obtained results, the results were grouped under experience based groups of the participants and professional cadre of respondents. The most and least important factors in groups were achieved through ranking results. Prediction model for estimating actual project duration was developed; a real case study was tested the accuracy of proposed model.

AlSehaimi et al. [7] aimed to demonstrate the root cause of delay in construction which is tended to be descriptive and explanatory, making it inadequate for solving persistent managerial problems in construction. It is contended that many problems in construction could be mitigated through alternative research approaches. Such prescriptive research methods can assist in the development and implementation of innovative tools tackling managerial problems of construction, including that of delay.

Ezeldin and Abdel-Ghany [16] focused on the causes of construction delays in the Egyptian construction industry. The first main objective of the research is to identify and rank the major causes of delays for engineering projects. The second main objective is to determine the party responsible for the main causes of delays. The research was conducted in three phases. The first phase included unstructured interviews with practitioners involved in the Egyptian construction industry. The second phase consisted of a survey for a sample of thirty-five (35) professional experts using a customized questionnaire. These experts represented the different parties of the construction industry; namely, the Contractor, the Employer, and the Consultant/ Project Manager. The third phase of the research covered the analysis of the data collected, in order to determine the frequency and ranking of the causes of delays. The analysis of the results also included the party responsible of the different causes. The results revealed that the causes of delays can be grouped into five (5) main categories: (1) Construction related causes; (2) Managerial related causes; (3) Political related causes; (4) Financial related causes; and (5) Technical related causes. The top 12 causes included 3 construction, 7 managerial, 1 political and 1 financial related causes. The contractor and the Employer were found to be responsible each of 5 of the top 12 causes. The remaining two were found to be the responsibility of a third party.

Hwang and Lim [31] aimed to identify CSFs in terms of the different project players and their objectives in the context of Singapore’s construction industry. To achieve this objective, 32 CSFs were first identified and classified into four major categories: (1) project characteristics, (2) contractual arrangements, (3) project participants, and (4) interactive processes. Then the analytic hierarchy process (AHP) method was employed to establish a hierarchical model of the factors’ relative importance. To facilitate systematic analysis on their importance, 12 experts with at least 10 years of industry experience were surveyed; then, through the use of the Expert Choice software, the CSFs addressing budget performance, schedule performance, quality performance, and overall project success were identified.

Arif and Morad [10] described “concurrent delays” as situation when more than one delay occurs simultaneously, either of which would alone delay the overall project. The responsibility of concurrent delays is usually attributable to opposing parties to the contract, such as owner and contractor. This often leads to disputes concerning the extent to which each of the parties is responsible for project delay. They overviewed and compared various approaches adopted by courts with respect to ruling on concurrent delay claims and apportionment under different legal system legal systems including the United States (U.S.), Canada, United Kingdom (U.K.), and Australia.

Bahadir and Mykhaylova [13] presented a simple two-sector model that incorporated housing supply which is subject to several types of delays. On average, it takes 6 months to get approved for a residential building permit and another 2–4 quarters to complete a construction project. These observations show the effect of these delays is not uniform: while they amplify the response of house prices to demand shocks, they dampen the effects of housing supply shocks. The results highlight the importance of capturing the nature and the persistence of the shocks when studying the effects of construction sector delays on housing market dynamics.

Magdy et al. [41] analyzed delays in construction projects that initiated to investigate the level of awareness, frequency of usage, information needs, complexity of application, and success rate of each CPM DAM used in the Egyptian construction market. It was conducted through a triangulation approach for data collection that employed a quantitative questionnaire and a qualitative interview. Distribution of questionnaires followed a thorough analysis of the market structure and size of organizations. Collected data were analyzed by SPSS software.

Braimah [14] reported (1) most contractors prefer to use linked bar chart format for their baseline programs over conventional critical path method (CPM) networks; (2) baseline programs are developed using planning software packages; (3) manpower loading graphs are not commonly developed as part of the main deliverables during preconstruction stage planning; and (4) baseline program development involves many different experts within construction organizations as expected.

González et al. [22] analyzed delay causes in activities that were not completed as scheduled and contributed a methodology to examine the qualitative (delay causes) and quantitative (time performance) dimensions of the delay issue. They proposed two indicators, as follows: (1) reason for noncompliance (RNC) as an indicator that characterizes scheduling failures, and (2) delay index (DI) as a time-performance indicator that described the impacts of delay on critical and noncritical activities.

Albogamy et al. [5] aimed to provide a new methodology for a client risk management model (CRMM) due to time delay. The study included the development of a framework by integrating the findings from the literature review and a construction industry survey. A client risk analysis system is developed by integrating the analytical hierarchy process and Monte Carlo simulation underpinned within Risk program. A case study was used to demonstrate the methodology and found that it was capable of managing the risks with a suitable risk mitigation strategy and supports the proactive actions at the design stage of a construction project from the client aspect.

Ruqaishi and Bashir [52] investigated the causes of delay in construction projects in oil and gas processing facilities in Oman and serves as a case study for the Gulf Cooperation Council (GCC) countries. Using a questionnaire, data were collected from 59 project managers employed in different organizations in the oil and gas industry in Oman. The survey results showed a high degree of agreement among the perceptions of project stakeholders, clients, contractors, and consultants on the causes of project delay, and there is no evidence to suggest that the causes of project delay differ significantly according to organization size or organizational ownership. Moreover, seven factors were identified as the major causes of project delay. Although six of these identified elements are general factors that can account for delay in any project in any industry, one of them poor interaction with vendors in the engineering and procurement stages was found to be unique to construction projects in the oil and gas industry.

Lopes et al. [40] reported that the increase in using equipment in various construction activities causing delay, planning the maintenance of this equipment has become extremely important as this aids meeting project deadlines.

Gunduz et al. [25] proposed a decision support tool for contractors before the bidding stage to quantify the probability of delay in construction projects in Turkey by using the Relative Importance Index (RII) method incorporated into fuzzy logic. 83 delay factors were identified, categorized into 9 major groups through a detailed literature review process as well as interviews with experts from the construction industry. The relative importance of these delay factors and groups was quantified by using the Relative Importance Index method. The ranking of the factors and groups was demonstrated according to their level of effect on delay. A delay assessment model was proposed using the fuzzy set theory by taking into account the delay factors characterized in construction projects.

Jung et al. [33] reported that it is very important to be able to estimate the delay that would result from such severe weather because construction contracts generally differentiate between weather delays that can be anticipated and those that cannot. A simulation model was developed by integrating the weather generation model and a construction schedule simulation model by using a discrete event simulation method, and a case study was conducted to validate the results of weather delay estimation and to analyze the degree to which vertical weather variations affect the schedule of building construction projects. The contribution of study is the proposal of a method based on analyzing the pattern of weather delays in building construction projects.

Larsen et al. [37] analyzed the factors that project managers experience as having the greatest effect on time, cost, and quality, and to discover whether the effects of these factors are significantly different from each other. A questionnaire with 26 factors identified from interviews was sent to employed project managers. Factors were ranked using the Relative Importance Index and tested for significant differences using Friedman’s test. From the findings it was determined that the most influential factor for time is unsettled or lack of project funding; for cost, errors or omissions in consultant material; and for quality, errors or omissions in construction work.

Tumi et al. [58] mentioned the cause “indicative of experiences” while other researches mentioned a cause for contractor experience, owner experience, designer experience and consultants experience each at a time as a separate cause so each of the 4 causes “ inadequate contractor experience work causing error”, “inadequate experience of designers”, “lack of experience of consultant in construction projects” and “lack of experience of owner in construction projects”. Fallahnejad [17] mentioned the cause “labor injuries” as a part of a cause “accidents during construction – labor injuries – infectious disease”. Marzouk and El-Rasas [43]mentioned the two causes “equipment availability and failure” as one cause while in the accumulated factors it was mentioned separately as “equipment failure (breakdown)” and “tool availability”. Faridi and El-sayegh [18] mentioned the cause “changes in drawings” and “changes in specifications” as two separate cause while the accumulated cause is called “change in drawing and specifications”. Fugar and Agyakwah-baah [20] mentioned the two causes “poor site management” and “poor supervision” as two separate causes while the accumulated cause is called “poor site management and supervision” as one cause. Ramanathan et al. [51] mentioned the cause “slowness of the owner decision making process” 3 times in the 113 causes. It was mentioned the cause “low speed of decision making” in the owner/client group and the cause “slowness of owners decision making process” in the contractual relationship group and the cause “supervision too late & slowness in making decision” in the consultant group and mentioned the cause “preparation and approval of shop drawings, samples” 3 times in the 113 causes. It was mentioned the cause “long waiting time for approval of drawings” in the owner/client group, the cause “preparations and approval of shop drawing” in the scheduling & controlling group.

The 290 causes of delay that have been collected from the literature review taking into account not to repeat any cause are analyzed and causes are ranked according to occurrence in each research. Often, the number of mentioning each cause in the overall researches is related to the importance of the factor, for example the factor “Weather conditions” is an important factor which is not related to the type of construction, location or cost; therefore, 88% of the studied researches mentioned this factor with researches ranked it as a major factor leading to unanticipated delays and has a direct effect on delay. “Shortage (availability) in construction materials” with percentage 71%, “Shortage in equipment/insufficient numbers” with percentage 54% support the view that construction industry problems in developing economies are problems of shortages or inadequacies in industry infrastructure (mainly supply of resources) as shown in Table 1.

Table 1. Top twenty overall mentioned delay causes in the literature review.
Rank Delay factor description Related category item Number of occurrence
01 Weather conditions External 21
02 Shortage (availability) in construction materials Material 17
03 Slowness of the owner decision making process Owner 15
04 Poor site management and supervision by contractor Contractor 15
05 Shortage of labor Labor 14
06 Accidents/mistakes during construction External 14
07 Slow delivery of materials Material 14
08 Construction methods Contractor 13
09 Shortage in equipment/insufficient numbers Equipment 13
10 Financing by contractor during construction Financing 12
11 Preparation and approval of shop drawings, samples Owner 12
12 Inadequate contractor experience causing error Contractor 12
13 Low productivity level work Labor 12
14 Obtaining permits from municipality (government) Rules & regulations 12
15 Ineffective planning and scheduling of project by contractor Scheduling and controlling 12
16 Delays in contractors progress payment by owner Financing 11
17 Unrealistic (unreasonable) contract time (duration) & requirements imposed Contract 11
18 Owner financial problems/client finance/economic ability for the project Financing 10
19 Change orders by owner during construction (variation) Owner 10
20 Legal/industrial disputes between various parties in the construction project (claims) Contractual relationships 10

The cause “Fraudulent practices” has an indirect and unimportant effect in the construction industry since the countries and project managers nowadays take strong legal actions against swindling and fraud. The causes “Global financial crisis” and “Hurricane” has almost no effect as it is a rare phenomenon that happens at mostly once in the projects lifetime. But it may have a big effect if it randomly happened during a project lifetime and it could have bad effects up to end of the project totally as shown in Table 2.

Table 2. Least twenty overall mentioned delay causes in the literature review.
Rank Delay factor description Related category item Number of occurrence
01 Fraudulent practices External 1
02 Delay in honoring payment certificates Financing 1
03 Global financial crisis Financing 1
04 Late payment to subcontractor by the main contractor Financing 1
05 Issues regarding client approval Owner 1
06 Improper selection of subsequent consultants Owner 1
07 Frequent change of client managers Owner 1
08 Non-adherence of material specifications provided by client Contractor 1
09 Low ability of contractor to provide imported material Contractor 1
10 Absenteeism of laborers Labor 1
11 Staffing problems Labor 1
12 Disagreement on design specifications Design 1
13 Geological problems on site Site 1
14 Disturbance to public activity Site 1
15 Previous working relationships of consultant Contractual relationship 1
16 Unrealistic contract price Contract 1
17 Delay in finalization of rates for extra items Project 1
18 Hurricane External 1
19 Public holidays External 1
20 No planning before project starts Scheduling and controlling 1

## 3. Research objective

This research aimed to: (1) Identify the most important and least important causes of delay that affects highway constructions in Egypt; (2) Identify the severity of the delay causes from contractor, consultant and site/design engineer’s perspective; (3) Identify the possible ways to avoid the delay to highway constructions in Egypt; (4) Compare of the results from the questionnaire survey with a case of study on road project in Egypt; and (5) Make recommendations in order to minimize or control delays in road construction projects.

## 5. Project delay causes and groups

Table 3. Categorized groups that cause delay in construction projects.
S/N Category group item Related cause ID Total number of causes
01 Financing related cause group 01: 15 15
02 Owner related cause group 16: 38 24
03 Contractor related cause group 39: 58 20
04 Labor related cause group 59: 73 15
05 Design related cause group 74: 99 26
06 Site related factors category 100: 126 27
07 Contractual relationships related cause group 127: 154 28
08 Contract related cause group 155: 167 13
09 Project related cause group 168: 181 14
10 External related cause group 182: 205 24
11 Equipment related cause group 206: 215 10
12 Rules & regulations related cause group 216: 234 19
13 Consultant related cause group 235: 248 13
14 Scheduling and controlling related cause group 249: 278 30
15 Material related cause group 279: 293 15
Total 01: 293 293

## 6. Questionnaire survey

A number of 500 questionnaires were distributed and were filled out by three hundred eighty-nine (389) highly experienced construction professionals including technical consultants, main contractors and sub-contractors, and site/design engineers with a response rate of 78 %. One hundred eighty-six (186) valid responses were obtained. The collected data were analyzed through Relative Importance Index (RII) method. The analysis included ranking the different causes according to the relative importance indices. The analysis revealed the most contributing factors and categories causing delays.

Road projects in Egypt have four participants: (1) The government as the owner; (2) A consultant team usually from the faculty of engineering as the consultant; (3) Directorate of road and transportation as the supervisor on the implementation; and (4) Contractors of road projects as the real implement. The respondents samples had the three last participants excluding the owner (the government) with the one point of view.

Respondents profiles are included in the following tables. Table 4 shows the profession of the respondents, consultants, contractors or site/design engineers. Table 5 shows the gender of the respondents. Table 6 shows the years of experience of the respondents.

Table 4. Profession of respondent.
S/N Professional cadre of respondents No of respondents Percentage (%)
01 Consultants 36 19.35
02 Site/design engineers 19 10.20
03 Contractors 131 70.45
Total 186 100%

Table 5. Gender of respondent.
S/N Professional cadre of Respondents Male Female
01 Consultants 33 3
02 Site/design engineers 102 29
03 Contractors 14 5
Total 149 37
Percentage (%) 80.10 19.90

Table 6. Respondents years of experience.
S/N Years of experience No of respondents Percentage (%)
01 Less than 5 Years 38 20
02 5:10 Years 41 22
03 10:20 Years 57 31
04 20:30 Years 32 17
05 Above 30 Years 18 10
Total 186 100%

### 6.1. Analysis and discussions

The causes of delay in road construction projects in Egypt will be looked at from different perspectives. It will examine the data provided by respondents and that will be the basis for case selection.

#### 6.1.1. Ranking of delay causes

To provide a degree of importance for each delay cause, an important index was calculated in the same way as shown in Eq. (1). This formula was used by Aibinu and Odeyinka [4] and Doloi et al. [15].

 ${\displaystyle {RII}_{k}^{i}={\frac {{\sum }_{{\mbox{i}}=1}^{5}W}{A\times N}}}$
(1)

where ${\textstyle {RII}_{k}^{i}}$ is the yearly experience of Relative Importance Index of each factor for each group of respondents; W is the weighting given to each factor by the respondents (ranging from 1 to 5); A is the highest weight (i.e. 5 in this case); and N is the total number of respondents.

Overall Relative Importance Index “ORII” for each factor of all respondents representing can be calculated by Eq. (2) This formula was used by Aziz [12] and the formulation consists of three groups as follows: “Consultants group (i = 3)”; “Site/design Engineers group (i = 2)”; and “Contractors group (i = 1)” considering all years of experiences of respondents together; which is calculated as a weighted average by RII from Eq. (1).

 ${\displaystyle ORII=\sum _{{\mbox{i}}=1}^{{\mbox{i}}=3}{\frac {i}{6}}\times \left[{\frac {{\sum }_{{\mbox{k}}=1}^{{\mbox{k}}={\mbox{K}}}\left(k\times {\mbox{RII}}_{\mbox{k}}^{\mbox{i}}\right)}{{\sum }_{{\mbox{k}}=1}^{{\mbox{k}}={\mbox{K}}}(k)}}\right]}$
(2)

where ORII is the weighted Overall Relative Importance Index for each factor; which is calculated based upon total years of experiences of all grouped respondents together; k is the number that represents’ years of experience of grouped respondents (from first year of experience k = 1 to last year of experience k = K); i   is the type of grouped respondents; and ${\textstyle {\mbox{RII}}_{\mbox{k}}^{\mbox{i}}}$ is the yearly experience percentage of Relative Importance Index of each factor; which is calculated separately for corresponding year (k) of grouped respondents experience and calculated by Eq. (1). The causes are arranged in ascending order of ranks, and causes with highest ORII or rank 1 indicate that it has the maximum impact on the delay while the least rank indicates that it has the least impact on delay.

6.1.1.1. Analysis of overall results

Financial problems, shortages in equipment, construction materials, skilled operators, inadequate experiences, reworks, changes or errors in design, delays in design submittal, soil and underground problems in investigation or management or expropriation, physical obstructions are the reasons for delay according to the questionnaire results. The cause (conflict, war, revolution, riot and public enemy) with revolution as in the 25 January revolution in Egypt made it to be from the top twenty causes of delay unlike the majority of the researches which have no weight. Showing these causes to be the most important 20 causes of all 293 causes in Table 7.

Table 7. Overall RII and ranking of top 20 time delay causes.
Rank Group ID Delay cause description Related group item Overall Relative Importance Index (ORII)
01 F1 Owner financial problems/client finance/economic ability for the project Financing 0.886
02 E1 Shortage in equipment/insufficient numbers Equipment 0.824
03 C11 Inadequate contractor experience (work) causing error Contractor 0.816
04 M1 Shortage (availability) in construction materials Material 0.814
05 E4 Equipment failure (breakdown) Equipment 0.813
06 D1 Design errors made by designers (due to unfamiliarity with local conditions and environment) Design 0.810
07 S2 Mistakes in soil investigation Site 0.808
08 C2 Poor subcontractor performance/delays Contractor 0.805
09 D17 Rework due to change of design or deviation order Design 0.804
10 C7 Poor site management and supervision by contractor Contractor 0.797
11 D11 Wrong or improper (poor) (inappropriate) design Design 0.797
12 S24 Faulty soil investigation paper Site 0.795
13 E2 Lack of skilled operators for specialized equipment Equipment 0.794
14 O20 Slow land expropriation due to resistance from occupants Owner 0.791
15 E14 Conflict, war, revolution, riot, and public enemy External 0.791
16 M8 Reworks due to defects in construction materials Material 0.788
17 O4 Design changes by owner or his agent during construction Owner 0.783
18 E13 Physical obstructions External 0.781
19 C2 Delay of design submittal from consultant Consultant 0.781
20 S6 Unexpected underground condition Site 0.780

Working relationships have almost no effect on delay, and workers personal health, culture, religion or nationality, segmentation of lands, flood program, coastal control line permit, bankers policy, holidays are causes which do not exist or do not have a presence in the real road project in Egypt which is Consistent with road project circumstances in Egypt as shown in Table 8 for the least 20 time delay causes.

Table 8. Overall RII and ranking of least 20 time delay causes.
Rank Group ID Delay cause description Related group item Overall Relative Importance Index (ORII)
274 E18 Necessary variations External 0.597
275 C27 Previous working relationship of owner Contractual relationship 0.596
276 C14 Unfair subcontractor relationships with employees Contractual relationship 0.591
277 C15 Previous working relationships of consultant Contractual relationship 0.591
278 R8 Coastal construction control line permit Rules & Regulations 0.590
279 E6 Problems with neighbors External 0.584
280 P6 Function or end use (office, residential, industrial) Project 0.580
281 L9 Staffing problems Labor 0.578
282 O1 The unavailability of financial incentives for contractor to finish ahead of schedule Owner 0.573
283 F9 Changing of bankers policy Financing 0.572
284 L4 Labor injuries Labor 0.563
285 C13 Laborers personal conflict Contractual relationship 0.560
286 E15 Public holidays External 0.542
287 E7 Infectious disease External 0.514
288 E8 Segmentation of the west bank and limited movement between areas External 0.481
289 R11 National flood insurance program Rules & Regulations 0.472
290 E4 Social, religions and cultural factors External 0.462
291 L3 Nationality of laborers Labor 0.447
292 R10 Failure of RIBA plan of work application Rules & Regulations 0.443
293 R9 Florida administrative code Rules & Regulations 0.431

6.1.1.2. Analysis of delay groups according to overall results

The groups of delay causes were analyzed based on the overall results. The group importance index was calculated as the average of the importance indices for the delay causes in the groups. The ranked groups of delay causes and their corresponding importance index are shown in Table 9 showing the equipment related group to be the first group affecting the delay and the rules and regulations group to be the last affecting delay.

Table 9. Groups importance index for overall results.
Rank Delay group Group importance index
01 Equipment related group 0.752
02 Design related group 0.739
03 Contractor related group 0.728
04 Material related group 0.723
05 Contract related group 0.718
06 Consultant related group 0.707
07 Financing related group 0.699
08 Site related group 0.698
09 Scheduling and Controlling related group 0.686
10 Owner related group 0.680
11 Contractual relationship related group 0.668
12 Labor related group 0.665
13 Project related group 0.660
14 External related group 0.641
15 Rules & regulations related group 0.633

6.1.1.3. Analysis of delay causes according to each parties result

In order to analyze the delay causes by each party independently. The 19 contractors, 36 consultants and 131 site/design engineer data were separated and analyzed individually by calculating the importance index. The most important 20 causes organized by each party is shown in Table 10 and Table 11 showing the importance index of each cause and the rank of the top ten causes and the least ten causes in the overall results .

Table 10. Ten most important causes by project parties.
Rank Consultant ORII Contractor ORII Site/design engineer ORII
01 Owner financial problems/client finance/economic ability for the project 0.839 Owner financial problems/client finance/economic ability for the project 0.947 Owner financial problems/client finance/economic ability for the project 0.890
02 Conflict, war, revolution, riot, and public enemy 0.817 Cash- flow problems during construction 0.884 Shortage in equipment/insufficient numbers 0.837
03 Slow land expropriation due to resistance from occupants 0.800 Unexpected underground condition 0.853 Inadequate contractor experience (work) causing error 0.834
04 Mistakes in soil investigation 0.794 Faulty soil investigation paper 0.853 Equipment failure (breakdown) 0.831
05 Difficulty of coordination between various parties (contractor, subcontractor, owner, consultant) working on the project 0.794 Mistakes in soil investigation 0.842 Rework due to change of design or deviation order 0.829
06 Poor subcontractor performance/delays 0.789 Poor subcontractor performance/delays 0.832 Design errors made by designers (due to unfamiliarity with local conditions and environment 0.826
07 Unexpected underground condition 0.789 Lack of experience of consultant in construction projects 0.832 Shortage (availability) in construction materials 0.823
08 Shortage in equipment/insufficient numbers 0.789 Physical obstructions 0.821 Wrong or improper (poor) (inappropriate) design 0.811
09 Design changes by owner or his agent during construction 0.778 Obtaining permits from municipality (government) 0.821 Poor site management and supervision by contractor 0.809
10 Changes in clients requirements 0.778 Excessive bureaucracy in project owned operation 0.821 Lack of skilled operators for specialized equipment 0.809

Table 11. Ten least important causes by project parties.
Rank Consultant ORII Contractor ORII Site/design engineer ORII
284 Inadequate progress review 0.561 Previous working relationship of owner (275) 0.505 Laborers personal conflict (285) 0.557
285 Lack of trade’s skill 0.556 Necessary variations 0.505 Labor injuries 0.550
286 Infectious disease 0.544 National flood insurance program 0.484 Public holidays 0.533
287 Coastal construction control line permit 0.528 Public holidays 0.474 Infectious disease 0.516
288 National flood insurance program 0.494 Failure of RIBA plan of work application 0.453 Segmentation of the west bank and limited movement between areas 0.496
289 Failure of RIBA plan of work application 0.489 Infectious disease 0.442 Social, religions and cultural factors 0.476
290 Segmentation of the west bank and limited movement between areas 0.478 Nationality of laborers 0.421 National flood insurance program 0.464
291 Nationality of laborers 0.472 Social, religions and cultural factors 0.421 Nationality of laborers 0.444
293 Social, religions and cultural factors 0.433 Segmentation of the west bank and limited movement between areas 0.379 Failure of RIBA plan of work application 0.429

6.1.1.4. Analysis of groups according to each parties results

The groups of delay causes were analyzed based on each parties response. The group importance index was calculated for each party separately. Table 12 shows the ranking of the three parties view for the groups importance index.

Table 12. The ranking of the groups according to each party.
Rank Consultant ORII Contractor ORII Site/design engineer ORII
1 Equipment related cause 0.716 Financing related cause 0.716 Equipment related cause 0.760
2 Contract related cause 0.716 Equipment related cause 0.765 Design related cause 0.752
3 Material related cause 0.707 Consultant related cause 0.756 Contractor related cause 0.740
4 Design related cause 0.702 Site related cause 0.724 Material related cause 0.731
5 Contractor related cause 0.701 Design related cause 0.717 Contract related cause 0.721
6 Contractual relationships related cause 0.680 Contract related cause 0.704 Consultant related cause 0.708
7 Consultant related cause 0.679 Material related cause 0.700 Financing related cause 0.705
8 Site related cause 0.676 Contractor related cause 0.696 Site related cause 0.701
9 Owner related cause 0.675 Scheduling and controlling 0.678 Scheduling and controlling 0.690
10 Scheduling and controlling 0.675 Owner related cause 0.645 Owner related cause 0.686
11 Financing related cause 0.668 Labor related cause 0.637 Labor related cause 0.671
12 Labor related cause 0.661 Contractual relationships related cause 0.635 Contractual relationships related cause 0.669
13 Project related cause 0.658 Rules & regulations related cause 0.633 Project related cause 0.666
14 External related cause 0.634 Project related cause 0.625 External related cause 0.646
15 Rules & regulations related cause 0.624 External related cause 0.618 Rules & regulations related cause 0.636

6.1.1.5. Ranking of delay causes under each group for overall results

• Equipment group

Equipment group is ranked the first group affecting delay for the overall results as shown in Table 9. Under the equipment group, 10 causes are listed. Table 13 shows the top five affecting causes on delay in the equipment group.

• Design group

Table 13. Top 5 ranking of causes under equipment group for the overall results.
Overall rank Delay group No in group Cause ORII
2 Equipment E1 Shortage in equipment/insufficient numbers 0.824
5 Equipment E4 Equipment failure (breakdown) 0.813
13 Equipment E2 Lack of skilled operators for specialized equipment 0.794
24 Equipment E3 Equipment productivity (efficiency) 0.776
56 Equipment E9 Improper equipment 0.746

Design group is ranked the second group affecting delay for the overall results as shown in Table 9. Under the design group, 26 causes are listed. Table 14 shows the top five affecting causes on delay in the design group.

• Contractor group

Table 14. Top 5 ranking of causes under design group for the overall results.
Overall rank Delay group No in group Cause ORII
6 Design D1 Design errors made by designers (due to unfamiliarity with local conditions and environment) 0.810
9 Design D17 Rework due to change of design or deviation order 0.804
11 Design D11 Wrong or improper (poor) (inappropriate) design 0.797
21 Design D26 Change in drawings & specifications 0.778
27 Design D13 Inadequate experience of designers 0.772

Contractor group is ranked the third group affecting delay for the overall results as shown in Table 9. Under the contractor group, 20 causes are listed. Table 15 shows the top five affecting causes on delay in the contractor group.

• Material group

Table 15. Top 5 ranking of causes under contractor group for the overall results.
Overall rank Delay group No in group Cause ORII
3 Contractor C11 Inadequate contractor experience (work) causing error 0.816
8 Contractor C2 Poor subcontractor performance/delays 0.805
10 Contractor C7 Poor site management and supervision by contractor 0.797
22 Contractor C5 Rework because of errors during construction 0.777
45 Contractor C12 Non-adherence of material specifications provided by client 0.757

Material group is ranked the fourth group affecting delay for the overall results as shown in Table 9. Under the material group, 15 causes are listed. Table 16 shows the top five affecting causes on delay in the material group.

• Contract group

Table 16. Top 5 ranking of causes under material group for the overall results.
Overall rank Delay group No in group Cause ORII
4 Material M1 Shortage (availability) in construction materials 0.814
16 Material M8 Reworks due to defects in construction materials 0.788
31 Material M2 Materials changes in types and specifications during construction 0.769
40 Material M6 Low quality of construction materials 0.760
43 Material M3 Slow delivery of materials 0.759

Contract group is ranked the fifth group affecting delay for the overall results as shown in Table 9. Under the contract group, 13 causes are listed. Table 17 shows the top five affecting causes on delay in the contract group.

• Consultant group

Table 17. Top 5 ranking of causes under contract group for the overall results.
Overall rank Delay group No in group Cause ORII
23 Contract C13 No adherence to contract conditions 0.776
25 Contract C7 Unrealistic (unreasonable) contract time (duration) & requirements imposed 0.774
37 Contract C6 Unrealistic contract price 0.763
92 Contract C2 Mistakes and discrepancies in contract documents 0.728
99 Contract C1 Poor contract management 0.724

Consultant group is ranked the sixth group affecting delay for the overall results as shown in Table 9. Under the consultant group, 14 causes are listed. Table 18 shows the top five affecting causes on delay in the consultant group.

• Financing group

Table 18. Top 5 ranking of causes under consultant group for the overall results.
Overall rank Delay group No in group Cause ORII
19 Consultant C2 Delay of design submittal from consultant 0.781
52 Consultant C12 Lack of experience of consultant in construction projects 0.753
54 Consultant C11 Delay in approving major changes in the scope of work by consultant 0.749
57 Consultant C1 Waiting instructions from consultant 0.746
75 Consultant C14 Consultant or architect’s reluctance for change 0.737

Financing group is ranked the seventh group affecting delay for the overall results as shown in Table 9. Under the financing group, 15 causes are listed. Table 19 shows the top five affecting causes on delay in the financing group.

• Site group

Table 19. Top 5 ranking of causes under financing group for the overall results.
Overall rank Delay group No in group Cause ORII
1 Financing F1 Owner financial problems/client finance/economic ability for the project 0.886
28 Financing F2 Payment of completed work 0.771
50 Financing F15 Late payment to subcontractor by the main contractor 0.754
60 Financing F12 Material and labor wage escalation (inflation) 0.744
66 Financing F7 Financing by contractor during construction 0.742

Site group is ranked the eighth group affecting delay for the overall results as shown in Table 9. Under the site group, 27 causes are listed. Table 20 shows the top five affecting causes on delay in the site group.

• Scheduling and controlling group

Table 20. Top 5 ranking of causes under site group for the overall results.
Overall rank Delay group No in group Cause ORII
7 Site S2 Mistakes in soil investigation 0.808
12 Site S24 Faulty soil investigation paper 0.795
20 Site S6 Unexpected underground condition 0.780
41 Site S4 Effects of subsurface conditions (e.g., soil. High water table, etc.) 0.759
42 Site S27 Poor site layout 0.759

Scheduling and controlling group is ranked the ninth group affecting delay for the overall results as shown in Table 9. Under the scheduling and controlling group, 30 causes are listed. Table 21 shows the top five affecting causes on delay in the scheduling and controlling group.

• Owner group

Table 21. Top 5 ranking of causes under scheduling and controlling group.
Overall rank Delay group No in group Cause ORII
30 Scheduling and Controlling S11 No planning before project starts 0.769
59 Scheduling and Controlling S20 Lack of program of works 0.745
77 Scheduling and Controlling S18 Improper or wrong cost estimation 0.735
89 Scheduling and Controlling S21 Poor professional construction management 0.729
90 Scheduling and Controlling S29 Inefficient capability of contractor staff management 0.729

Owner group is ranked the tenth group affecting delay for the overall results as shown in Table 9. Under the owner group, 23 causes are listed. Table 22 shows the top five affecting causes on delay in the owner group.

• Contractual relationships group

Table 22. Top 5 ranking of causes under owner group for the overall results.
Overall rank Delay group No in group Cause ORII
14 Owner O20 Slow land expropriation due to resistance from occupants 0.791
17 Owner O4 Design changes by owner or his agent during construction 0.783
29 Owner O15 Improper selection of subsequent consultants 0.770
33 Owner O5 Change orders by owner during construction (variation) 0.767
46 Owner O17 Delay in material to be supplied by the owner 0.756

Contractual relationships group is ranked the eleventh group affecting delay for the overall results as shown in Table 9. Under the contractual relationships group, 28 causes are listed. Table 23 shows the top five affecting causes on delay in the contractual relationships group.

• Labor group

Table 23. Top 5 ranking of causes under contractual relationships group for the overall results.
Overall rank Delay group No in group Cause ORII
49 Contractual relationships C5 Difficulty of coordination between various parties (contractor, subcontractor, owner, consultant) working on the project 0.755
82 Contractual relationships C2 The conflict between contractor and other parties (consultant & owner) 0.731
84 Contractual relationships C4 Poor organization of the contractor or consultant/inappropriate overall organizational structure linking to the project) 0.730
85 Contractual relationships C28 Lack of responsibilities 0.730
108 Contractual relationships C9 Insufficient communication between the owner and designer or other parties in design phases 0.718

Labor group is ranked the twelfths group affecting delay for the overall results as shown in Table 9. Under the labor group, 15 causes are listed. Table 24 shows the top five affecting causes on delay in the labor group.

• Project group

Table 24. Top 5 ranking of causes under labor group for the overall results.
Overall rank Delay group No in group Cause ORII
39 Labor L2 Labor skill 0.760
44 Labor L14 Foreman incompetence 0.758
64 Labor L1 Shortage of labor 0.743
68 Labor L13 Low productivity level work 0.741
135 Labor L11 Shortage of technical personnel/staff 0.704

Project group is ranked the thirteenth group affecting delay for the overall results as shown in Table 9. Under the project group, 14 causes are listed. Table 25 shows the top five affecting causes on delay in the project group.

• External group

Table 25. Top 5 ranking of causes under project group for the overall results.
Overall rank Delay group No in group Cause ORII
72 Project P9 Improper project feasibility study 0.739
81 Project P5 Unreasonable project time frame 0.732
112 Project P3 Complexity of project 0.716
165 Project P8 Ineffective delay penalties 0.689
192 Project P10 Type of project bidding and award (negotiation, lowest bidder) 0.673

External group is ranked the fourteenth group affecting delay for the overall results as shown in Table 9. Under the external group, 24 causes are listed. Table 26 shows the top five affecting causes on delay in the external group.

• Rules and regulations group

Table 26. Top 5 ranking of causes under external group for the overall results.
Overall rank Delay group No in group Cause ORII
15 External E14 Conflict, war, revolution, riot, and public enemy 0.791
18 External E13 Physical obstructions 0.781
62 External E20 Bribes (kickbacks) & personal interest (prejudices) “corruption” 0.744
121 External E22 Poor government judicial system for construction dispute settlement 0.711
146 External E16 Vandalism – robbery (security) 0.699

Rules and regulations group is ranked the fifteenth (last) group affecting delay for the overall results as shown in Table 9. Under the rules and regulations group, 19 causes are listed. Table 27 shows the top five affecting causes on delay in the rules and regulations group.

Table 27. Top 5 ranking of causes under rules and regulations group.
Overall rank No in group Cause ORII
26 R1 Obtaining permits from municipality (government) 0.774
35 R3 Building permits approval process 0.765
104 R2 Excessive bureaucracy in project owned operation 0.723
129 R17 Discrepancy between design specification and building codes 0.708
138 R4 Changes in laws and regulations 0.703

#### 6.1.2. Ranking of correlation

Two approaches are used to find the agreement between parties: Pearsons correlation coefficient among values of importance indices and Spearman’s rank correlation coefficient among ranks, Abd El-Razek et al. [1], and the agreement was calculated in a manner similar to that in the study of Abd El-Razek et al. [1].

Spearman’s rank correlation coefficient is a nonparametric measure of statistical dependence between two variables. It assesses how well the relationship between two variables can be described using a monotonic function. If there are no repeated data values, a perfect Spearman’s correlation of +1 or −1 occurs when each of the variables is a perfect monotone function of the other. The value of the Spearman’s rank correlation coefficient ranges from +1 (perfect positive correlation), to 0 (no correlation), to −1 (perfect negative correlation). The Eq. (3) is used in the analysis.

 ${\displaystyle \rho =1-{\frac {6\sum d^{2}}{\left(n^{3}-n\right)}}}$
(3)

where ρ = Spearman’s rank correlation coefficient; d = difference between the ranks indicated by two parties; and n = number of records as shown in Table 28.

Results show the agreement between the three parties to be a high agreement between consultant and site/design engineer with a coefficient (0.838) followed with a coefficient (0.783) for the agreement between the contractors and the engineers and last a coefficient (0.666) for the agreement between the contractor and the consultant, as shown in Table 29.

Table 29. The Spearman’s coefficient of agreement on delay causes and groups from results.
Parties Spearman’s coefficient of agreement on delay causes Spearman’s coefficient of agreement on delay groups
Consultants and site/design engineers 0.838 0.868
Contractors and site/design engineers 0.783 0.800
Contractors and consultants. 0.666 0.607

## 7. Proposed model

It might be noted that all these factors are originated by its category group, and this is expected since each party is trying to blame the other for causing delays. It was desired to compare the strength or the importance of each category; the weighted average value of category causes was calculated. The results are tabulated in Table 30 by using priority rule formula as shown in Eq. (4) which used by Aziz [12] is as follows:

 ${\displaystyle ERII=\left({\frac {{\sum }_{{\mbox{n}}=1}^{{\mbox{n}}={\mbox{N}}}(P_{\mbox{n}}\times {\mbox{ORII}}_{\mbox{n}})}{{\sum }_{{\mbox{n}}=1}^{{\mbox{n}}={\mbox{N}}}(P_{\mbox{n}})}}\right)}$
(4)

where ERII is the weighted Equivalent Relative Importance Index per category; ORIIn is the weighted Overall Relative Importance Index per factor of specific category; which is calculated based upon total years of experiences of all respondents; n is the number represents the factor number in the related category (from first factor of category n = 1 to last factor of category n = N); and Pn is the priority weight of the studied factor.

Table 30. Equivalent average Relative Importance Index of category.
Rank Category Item Equivalent Relative Importance Index Eq. (4)
01 Equipment related group 0.851
02 Design related group 0.838
03 Contractor related group 0.827
04 Material related group 0.822
05 Contract related group 0.817
06 Consultant related group 0.806
07 Financing related group 0.798
08 Site related group 0.797
09 Scheduling and Controlling related group 0.785
10 Owner related group 0.779
11 Contractual relationship related group 0.767
12 Labor related group 0.764
13 Project related group 0.759
14 External related group 0.740
15 Rules & Regulations related group 0.732

It is clear that the results of the 15 categories are almost consistent, where the categories are ranked from top to bottom as shown in Table 30. From previous analysis of collected data from road construction projects field, it will be predicted approximately the road construction actual duration of any new construction project before construction using Eqs. (5) and (6) as follows:

 ${\displaystyle PDC=1+\left({\frac {{\sum }_{{\mbox{j}}=1}^{{\mbox{j}}=4}(d_{\mbox{j}}\times {ERII}_{j})}{{\sum }_{{\mbox{j}}=1}^{{\mbox{j}}=4}({ERII}_{j})}}\right)}$
(5)

 ${\displaystyle PAD=PDC\times PSD}$
(6)

where PDC is the Predicted Delay Coefficient; ERIIj is the weighted Equivalent Relative Importance Index per category; dj is the each category impact according to the studied road construction project and it ranged between 0.00 and 1.00; PAD is the Predicted Actual Duration of the studied road construction project; and PSD is the total Planned Scheduled Duration before constructing the studied road construction project.

## 8. Case study

### 8.1. Basic information

This project consists of several types of works: (1) Surveying works, (2) Sanitary works, (3) Road works, (4) Electrical works, (5) Agricultural works and (6) Bridge works. In this paper road works only were studied as the paper is concerned with causes affecting delays in road construction projects.

### 8.2. Reasons for delays

The duration of the contract was 18 months and the Business volume port-to-date is 116 million pounds with 55 million for road works only. The project was delayed 12 months over estimated period for the following reasons: (1) The Signal Corps stopping work until the establishment of a new path for cables of Signal Corps; (2) Stopped working in more than one area because of the gas projects, water projects and electricity projects; (3) Getting started in extension of international cables, which led to stopping of work in one side totally; (4) Business interruption as a result of the events of the January 25 revolution; (5) Frequent attacks on workers by the people; and (6) Waste placed on both sides of the axis of Mahmudiya canal and along the path from the outlaws because of the lack of security presence.

### 8.3. Equivalent causes

The cause owner financial problems/client finance/economic ability for the project which is ranked the first from the research’s result has almost no effect in this case because the government contracted for this project with an assigning order contract which finance is present before making the assigning order.

If the 293 causes are divided into 5 zones as in the five-point Likert scale ranging from 1 (not important) to 5 (extremely important) so it could be considered that each 58.6 causes are a different zone ranging from not important to extremely important. Based on that the ranking of the cause is as follows in the Table 31.

Table 31. Importance zone for the delay causes.
Ranks of causes Zone
From ranking 1–59 Extremely important
From ranking 59–117 Important
From ranking 117–176 Moderate
From ranking 176–234 Somewhat important
From ranking 234–293 Not important

As for the first three causes referring to stop working because of establishment of a new path for cables of Signal Corps or stop working because of gas or water or electricity projects these reasons are consistent with the delay cause (Interfering of other projects) ranked no 231 for overall causes, 217 from consultants view, 231 from contractors view and 229 from site/design engineers view. The results of the questionnaire indicate that this cause is in the zone of Somewhat important causes which cannot be applied to the case of study that was considered from the top causes affecting the delay.

As for the cause no 4 regarding 25 January revolution and interruption of work due to it this reason is consistent with the delay cause (Conflict, war, revolution, riot, and public enemy) ranked no 15 from overall causes, 2 from consultants view, 41 from contractors view and 23 from site/design engineers view. This result is somehow consistent with the questionnaires result as it is from the top twenty causes of delay from the overall results.

As for the reason number 5 about frequent attack on workers and the reason number 6 regarding waste placed on both sides of the axis of Mahmudiya canal and along the path of the outlaws which was referred to the lack of security presence. These two reasons can be analyzed into more than the security presence. These reasons can be referred to culture of people throwing there wastes in the public roads, Poor site management and supervision by contractor banning any one from throwing things in their site but that can be explained as the site is almost 10 km which can be so hard to monitor and manage but is still the contractor’s responsibility, Inconvenient site area which is too big in this case, and environmental concerns and restrictions which do not apply fines for throwing wastes in the street. Besides absence of security, in the following Table the equivalent causes and there rankings for overall and each parties view are shown and there place in the importance zone.

From Table 32 the cause equivalent to the case study within the top 20 causes is Poor site management and supervision by contractor.

Table 32. Causes convenient to the case of study and their ranks.
N/S Cause Ranking Zone of importance
Overall results Consultant view Contractor view Site/design engineer view
1 Vandalism-robbery (security) 146 147 166 145 Moderate important
2 Social, religions and cultural factors 290 293 291 289 Not important
3 Poor site management and supervision by contractor 10 24 22 9 Extremely important
4 Inconvenient site area 222 247 237 210 Somewhat important
5 Environmental concerns and restrictions 241 239 252 230 Not important

Figure 2 and Figure 3 are examples for the delay because of interfering from the electrical projects and the signal corp projects and wastes thrown on the sides of the canal making obstructions to work causing delay.

 Figure 2. Example of electricity projects causing delays.

 Figure 3. Example of wastes on Mahmudiya canal sides.

### 8.4. Case study discussion and conclusion

From studying this project and analyzing the data, it was found that total planned project duration before start date was 18 working months, and total actual project duration after completion was 30 months, while total actual project duration is before constructing the studied project and after knowing the delay causes to calculate the predicted project duration from the following formulas:

 ${\displaystyle PDC=1.7098}$
(5)
 ${\displaystyle PAD=18{_{\ast }}1.7098\approx 30.77\quad {\mbox{Months}}}$
(6)

From analyzing and studying the studied road construction project, it was found that there is a variation between actual project duration increased than planned project duration by 66.67% and predicted actual project duration increased than planned project duration by 70.94% with accepted variance +0.77 months or +2.57%. Reasons of such increase, which are found the analyzing forms in questionnaires, are the same.

## 9. Conclusion

A study in palestine by Mahamid et al. [42] highlighted the following causes to be the top 5 causes from total 52 causes affecting delays in road construction projects: (1) Political situations; (2) Segmentation of the west bank and limited movements between areas; (3) Award project to lowest bid price; (4) Progress payment delay by owner; and (5) Shortage of equipment. These top causes identified for delay of road projects in palestine are ranked 195, 288, 192, 152 and 2 respectively from the total 293 cause that were studied in this research, and only the shortage of equipment is ranked to be from the top 5 causes in the two studies, meaning that for the same type of construction the top delay causes differ from a country to another.

The ranking of the top five groups from total 8 groups was as follows: (1) Project group; (2) Owner group; (3) Contractors group; (4) Consultants group; and (5) Design group.

These groups are ranked 13, 10, 3, 6, 2 from total 15 group which have only contractors group and design group to be from the first groups affecting delays. Questionnaire surveys using randomly sampled responses and analysis of data obtained from the responses is the approach taking by most researches.

Each study has different causes with different numbers and different groups with different numbers causing different ranking for causes and groups. Causes and groups causing delays are country, location and project specific and there are no root causes that can be taking for granted to be the most effective or the least effective delay causes.

The review findings show that the group and cause ranking differs based on the location between Egypt and Palestine. Sambasivan and Soon [53], Głuszak and Leśniak [21] stated that “The effects of delays in construction projects can be country specific” whereas other studies has proven that project characteristics may even be region-specific and that none of the studies is comparable to any other and each study has different rankings for the causes and the groups which is this research’s finding too.

The first step in reducing delays in road construction is to understand the root causes of the delay. The objective of this research was to identify the main causes of delay that affect road projects in Egypt. A literature review and expert interviews were conducted to identify the causes of delay. A compiled list of 293 causes given the combination of causes and groups in almost every construction project, was obtained and subjected to further quantitative evaluation in a questionnaire survey to confirm the causes and identify the most important causes of project delay. The most important causes affecting delay identified by the survey by using questionnaire that was conducted and the results were analyzed for the overall view and for each of the three parties who participated in the questionnaire (consultants, contractors, site/design engineers) separately to make an overall view of the causes of delay in road projects in Egypt.

From overall results it was found the owner financial problems was considered the first cause affecting delay in road projects in Egypt which in this case is considered the government, in comparison this cause was not included in the causes affecting delay in the case of study because in assigning contracts the funds of the project is already presence for that project. Generally large road projects are assigned to large contractors but the daily road projects with low funds face the problems of finance. Shortage in equipment, inadequate contractor experience, shortage in materials, equipment failure, design errors, mistakes in soil investigations, poor subcontractor performance, rework due to change of design, poor site management and supervision by contractor which was considered from the delay cases in the case of study are the most prominent delay causes for overall results.

From consultants view it was found the consultants ranked the owner financial problems to be the first cause affecting delay following it with conflict, war, revolution, riot and public enemy and this cause was ranked high only by the consultant which is a real fact going on in Egypt nowadays and has a big effect. Difficulty in coordination between different parties was ranked high only by the consultant who is a neutral party with no interest showing the compatibility between parties to be a difficult thing to happen. Also the cause of changes in clients requirements was given a high rank from consultants view.

From contractors view it was found that contractors also ranked the owner financial problems to be the first cause affecting delay following it by cash-flow problems during construction and the cause payment of completed work ranked from the top delay causes, confirming the issue of funds that affect the contractor. Lack of experience of consultant in construction projects was given a high rank from the contractors view blaming consultants for delays. From the top ranks are obtaining permits from municipality, excessive bureaucracy in project owned operation and building permits approval process which is the case of Egypt as the government has a routine which causes delay.

From site/design engineer’s view: Site/design engineers like the two other parties ranked the owner financial projects to be the first cause affecting delay. Engineers gave the causes that appear in site a high rank like shortages in equipment, materials and skilled operators, site management and supervision, contractors experience or subcontractors performance, mistakes in soil investigation or faulty soil report. And the causes connected to design like rework due to change of design, design errors made by designers, wrong or improper design, delay of design submittal from consultant, design changes by owner or his agent during construction was within the top delay causes from site/design engineers view.

Site/design engineers who were a new participant in the questionnaire respondents none of the reviewed literature took their view in the questionnaire conducted in the research the previous findings confirm the expression giving to those engineer’s (site/design) as those engineer’s are either in site as supervisors or in office as designer and there view was neglected.

From the overall results found in the questionnaire the equipment group was ranked the first group affecting delays in the road projects in Egypt since the equipment used in road pavements are heavy equipment and pricey so they are not available to most contractors or subcontractors who eventually do the work so insufficient numbers or failure there (breakdown) with no maintenance is a real problem facing road projects in Egypt followed by the design group which is repeated in some cases because of designer’s error, followed by contractors group as the first responsible parties group of the three common parties (owner, consultant and contractor), then materials group with its own problems of fluctuation prices or availability or quality, and contract group with nonadherence to contract condition or type in Egypt and the awarding of the project to the lowest bid price.

It appears to be a great agreement on delay causes between consultants and site/design engineer with the Spearman’s correlation coefficient equals (0.838) almost reaching the total agreement (1). The same with a big degree of agreement (0.783) between contractors and site/design engineer and finally a somehow low agreement between contractors and consultants with a coefficient (0.666) on the overall results. The correlation between research’s result and other results.

Finally, It was concluded that: (1) The Questionnaire surveys were used in the research and feasible method is taken into consideration for getting best results by using random samples and is the approach taken by most researches; (2) There are no root causes that can be taken for granted to be the most effective or the least effective delay causes; (3) None of the studies is comparable to another; and (4) Delay causes are specified according to country or location of the project or the type of the project.

## 10. Recommendations

An overview of the work of this paper can be accessed with the following recommendations based on the top results: (1) The owner financial problems make it important to pay the contractor’s dues on time to make it easy the contractors ability to finance the work; (2) Shortage in equipment makes it important to study the availability of the construction equipment needed whether it is for road construction or any other type of construction; (3) Inadequate contractor experience (work) causing error makes it necessary to Choose a contractor with a good reputation and sufficient experience in the field of work; (4) Shortage in construction materials like Bitumen in the road constructions can cause a big delay especially when the shortage is because of the prices fluctuation. Prices differences should be considered in the contracts; (5) Equipment failure (breakdown) that can due to lack of maintenance, insufficient workers or high prices of the equipment which make contractors depend on a certain equipment for a long time. Qualified workers should be assigned for dealing with equipments, having a regular maintenance (rare in Egypt) and assigning contractors with sufficient equipments; (6) Design errors made by designers due to unfamiliarity with local conditions and environment make it important for owner to employ experienced designers capable of adjusting all conditions with there design; (7) Soil investigation is the first step in decision of the design of road with traffic capacity, loads on road, number of layers of pavement. An appropriate Laboratory should be chosen; (8) Poor subcontractor performance delays so choosing experienced subcontractors with good reputation is necessary; (9) Rework due to change of design or deviation order makes it helpful to settle on the design and have the final approval of achieving the owner’s demand and the contractors capability of work; and (10) Poor site management and supervision by contractor There is a need for contractor to employ experts in management or improving the abilities of engineers responsible of management and supervision of site by Training courses.

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