Significant factors causing delay in the UAE construction industry

Construction delay is considered one of the most recurring problems in the construction industry. Delays have an adverse impact on project success in terms of time, cost, quality and safety. The effects of construction delays are not confined to the construction industry only, but influence the overall economy of a country like UAE, where construction plays a major role in its development and contributes 14% to the GDP. Thus, it is essential to define the most significant causes of delay in order to avoid or minimise their impact on construction projects. A detailed questionnaire was developed and used to get input from professionals associated with the UAE construction industry. The perspective of contractors and consultants has been analysed to rank the causes of delays based on their Relative Importance Index. Contractors and consultants were in agreement on the most significant causes of delays. The research revealed that 50% of the construction projects in UAE encounter delays and are not completed on time. The top 10 most significant causes of construction delays have been identified by this research. Approval of drawings, inadequate early planning and slowness of the owners' decision‐making process are the top causes of delay in the UAE construction industry.     

Incorporating rework into construction schedule analysis

Rework has been a primary cause of cost and schedule overruns in large construction projects. While several research efforts have analyzed the causes and effects of rework and provided guidelines to reduce rework, almost no research exists to analyze the impact of rework timing and quantity on schedule delays and to support decisions on cost effective recovery. This research presents a quantitative mechanism for schedule analysis considering rework. The mechanism has three aspects: (1) a new schedule representation of rework magnitude as negative percentage complete for affected activities, documented on the specific date on which the rework is detected; (2) a modified daily-windows delay analysis to apportion project delays among the responsible parties; and (3) an optimization technique for determining the least costly corrective action strategy that recovers project delays. The proposed approach is applied to a case study to demonstrate its ability to consider rework impact, in combination with other progress events by other project parties. This research offers an innovative quantitative approach to consider rework timing and amount in delay analysis and corrective action optimization.     

Structural equation model for investigating factors affecting delay in Indian construction projects

The rapid growth of the Indian construction sector over the last few decades and recurring failure in on-time delivery highlight the need for a systematic analysis of the factors influencing delay. A theoretical structural equation model representing the influence of four key latent variables on project delays in the Indian construction industry has been developed. Data collected from a questionnaire survey and personal interviews, with 77 valid responses from clients, contractors and designers or architects, were used to further formulate and analyse the model. The results of the structural equation model suggest that client’s influence is one of the most significant factors affecting time performance on Indian projects. Client’s influence is also found to be one of the key contributing factors resulting in lack of commitment and contractor’s inefficiency in the project. Lack of efficient construction planning plays the second key role in adverse time performance. While the effect of lack of commitment on contractor’s inefficiency is highly significant, neither of these two factors has any direct impact on time delay in projects. Contrary to the notion that the contractor is the only party responsible for delay in construction projects, the results clearly highlight the importance of the role of clients and technical expertise in planning in achieving satisfactory time performance on Indian projects. It is hoped that these research findings will contribute significantly to the Indian construction industry’s efforts in addressing the root causes of delay and enhancing the time performance on projects.     

The effect of political unrest on construction time for food grain warehouses in Bangladesh

A range of poorly understood factors affect actual construction time in the context of food sector projects in Bangladesh. One factor of particular interest is political unrest. The data for this study were obtained from a leading design and construction management company in Bangladesh. The sample size consisted of data for 104 food grain warehouse projects scattered all over the country. The effect of political unrest on construction time was analysed in conjunction with other known variables for actual construction time, such as increase in project cost and delay in procurement of construction materials. The effect of local political unrest on construction time was statistically significant even in the presence of project cost and procurement of materials variables. Political unrest could be included in prediction models used for finding out actual construction time of food grain warehouse projects in Bangladesh. Based on these findings, a prediction model for construction time for such projects is developed.     

Critical path effect based delay analysis method for construction projects

Assessing schedule delay's impact on total project duration to distribute delay liability remains a controversy. None of existing delay analysis methods is perfect because including an element of assumptions, subjective assessment and theoretical projection. Windows-based delay analysis methods are excellent in 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 (the EDAM method). The EDAM method performs delay analysis using extracted windows and determines delay impacts by considering the effects of delays on the critical path(s). According to its application to hypothetical cases and comparisons with other methods, the EDAM method is efficient in delay analysis and effective in solving concurrent delays and determining schedule shortened. The proposed EDAM method is a good alternative for schedule delay analysis for construction projects.     

Analysing factors affecting delays in Indian construction projects

Construction projects in India are experiencing widespread delays. Due to a dramatic shift in the capacity and volume of the Indian construction sector over the last decade, the need of a systematic analysis of the reasons of delays and developing a clear understanding among the industry professionals are highly crucial. Using a selected set of 45 attributes, this research first identified the key factors impacting delay in Indian construction industry and then established the relationship between the critical attributes for developing prediction models for assessing the impacts of these factors on delay. A questionnaire and personal interviews have formed the basis of this research. Factor analysis and regression modelling were used to examine the significance of the delay factors. From the factor analysis, most critical factors of construction delay were identified as (1) lack of commitment; (2) inefficient site management; (3) poor site coordination; (4) improper planning; (5) lack of clarity in project scope; (6) lack of communication; and (7) substandard contract. Regression model indicates slow decision from owner, poor labour productivity, architects' reluctance for change and rework due to mistakes in construction are the reasons that affect the overall delay of the project significantly. These findings are expected to be significant contributions to Indian construction industry in controlling the time overruns in construction contracts.     

An evaluation of construction time performance in the building industry

Building industries in many countries have been increasingly recognising the need for more efficient and timely completion of projects. Often, a number of unexpected problems and changes from original design arise during the construction phase, leading to cost and time overruns. Therefore, exploring the reasons for delay is one of the prerequisites of keeping the cost within budget and of good construction time performance. The primary objective of this paper is to identify the principal factors responsible for delays in the Hong Kong building industry, and determine their relative importance as perceived by different participant groups. A questionnaire survey, based on 83 previously identified delay factors, grouped into eight major factor categories, was conducted in early 1995. Responses from 78 construction personnel — from client, consultant and contractor organisations — suggest a strong consistency in perception between clients and consultants, for example as to the importance of the “poor site management and supervision” delay factor and the “contractor-related” delay factor category. However, there was a substantial disagreement between consultants and contractors, as well as between clients and contractors, in respect of the rankings of both the individual factors and the factor categories. Suggestions are given for more effective project management based on the observations. The results of this survey also provide a foundation for further research towards the development of an envisaged “construction time” prediction model for local building projects.     

A fuzzy logic approach to model delays in construction projects using rotational fuzzy fault tree models

Delays in construction projects are inevitable and, as a result, claims and disputes arise. Different causes of delay can come into play and therefore the need to identify and classify different causes of project delay arises. Different factors that contribute to project delay affect the likelihood of project delay in different degree of effectiveness. Fuzzy fault tree analysis (FTA) is suggested by this research to estimate the likelihood of project delay. Likelihood of delay membership function is further quantified using the weighted average defuzzification method. Two fuzzy logic models are implemented into the fuzzy FTA, using Visual Basic software: the models discussed in this research are Baldwin's rotational model and the Angular model. Comparison between the two fuzzy logic models has been carried out. Validation of the fuzzy FTA computer model is performed. Validation of the model was performed for adequacy and applicability of the model. On average, the validation performed by independent construction engineers and fuzzy logic experts produced satisfactory results. The computer software suggested by this study is an attempt to assess the likelihood of the project delay, which helps reduce delays in construction projects that can cause time loss.     

Fire services installation related contributors of construction delays

Delay is a common problem in the construction industry and there are several reasons that can contribute to delaying a project. In Hong Kong, completion of fire services installation is prerequisite to completing/finishing a building construction work. The fire services installation must be completed for application of an occupation permit for a building. Fail to obtain the permit on time would lead to construction delay. Apparently, fire services contractors play an important role in obtaining the occupation permit for a project completion. The economic losses due to construction delay could be very significant. This research identified, from a list of 49 pre-determined factors in nine categories (shown in Appendix A), the principal factors contributed to construction delays in a fire services installation. In particular, a questionnaire survey of 52 fire services contractors and 32 consulting engineers was conducted in order to obtain their professional judgements about the relative importance of the contributors of construction delay related to the fire services installation. The result showed that the principal contributors were: (1) improper site co-ordination and management of the electrical and mechanical installations, (2) lack of timely decision making of the client, and (3) defects identified during the fire services inspection by local authorities. In addition differing views were found between the consulting engineers and contractors on the areas identified were: (1) site management and supervision, (2) workload of the project staff, (3) the procedures for equipment approval, and (4) working experience of the parties. A monitoring and quality assurance system would be required in these areas to minimize the risk of the probable construction delay.     

巴勒斯坦建设项目延期和超支分析--加沙地带案例

成功的项目管理来自于对费用、质量和进度计划的控制.项目管理是施工过程中的关键部分.没有项目管理,即使是经过周密计划的项目也很有可能会失败.反之,在适当的时候运用有效的建设管理技术,可能将一个蹒跚不前的项目挽救过来.加沙地区的建设项目的设计人员常常没有技术上、环境上、社会上和统计上的数据来支持设计,而外国的承包商和咨询公司可能既不熟悉这个国家的材料和人力的资源情况,也不了解国家和当地的与项目有关的规章制度.因为以上和其他的一些原因,加沙地区的项目常常会工期延长,费用超支,从而减少预期的收益.本研究的目标是调查和分析加沙地带建设项目中延期的特征、时间长短和花费.研究数据来自于加沙地区的35个建设项目.本文首先探讨了导致延期的环境,基于责任制的延期分类,以及它们对项目费用和进度计划的影响.文章搜集数据,进行分析,并得到结论.本研究所得出的最重要的结论是对于减小工期延长和费用超支,最重要的措施是在项目最开始的阶段就对项目有充分的规划.     

Model-based dynamic resource management for construction projects

Excess resource idling can result in cost overruns, while low resource coverage or long lead-time in resource acquisition can delay the project schedule. Therefore, systematically managing this tradeoff is critical to ensure project delivery in time and within budget. In addition, to provide practically useful guidelines and tools, the dynamic construction process needs to be realistically represented. As an effort to address these issues, a model-based dynamic approach is proposed for construction resource management. The dynamics of construction progress and the tradeoff with resource coverage are identified. Then, the dynamic resource management model that has been developed using system dynamics is described. By simulating the model with heuristic and industry data, the effect of resource coverage on project performance is quantified and policy implications are obtained for dynamic resource management. Finally, the use of the model as an automated tool is demonstrated.     

Delays in construction projects: The case of Jordan

The construction industry is a major player in the economy, generating both, employment and wealth. However many projects experience extensive delays and thereby exceed initial time and cost estimates. A host of causes of construction delays in residential projects were identified and classified 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.     

Mathematical model to optimally solve the lift planning problem in high-rise construction projects

The availability of resources such as workforce and materials at each level of a high-rise construction project just before the commencement of building tasks is a crucial issue that might have direct impacts on project progress. To avoid delays caused by lack of human resources and construction materials, a construction management team always tries to find a better way to facilitate supply chain process specifically for construction projects facing a significant number of simultaneous and repetitive tasks. The other challenge in a high-rise construction project is vertical transportation that requires special machinery e.g. cranes or lifts, and also, maximizing their utilities. In this paper, it is tried to automate vertical transportation planning process in high-rise construction projects by introducing a platform that handles the entire lifting process. This platform considers (i) tasks attributes (e.g. required resources, location and commencement time) from the project schedule, (ii) lifting system specifications (e.g. travel speed, weight, and volume capacity) and (iii) project geometrics (e.g. current height of the project). In details, the introduced platform provides an optimized daily delivery plan by developing a Mixed-Integer Programming (MIP) model that covers workforce and construction materials. In this paper, the proposed platform is also tested using field data obtained from a 34-story construction project in Mashhad, Iran. The model could find a solution with 0% optimality gap in approximately 1 h, which is an acceptable amount of computational cost for the problem. The results show how the introduced platform can assist the construction management team to efficiently handle the supply process within stories while avoiding delays caused by a lack of resources required for each task.     

Incorporating the effect of weather in construction scheduling and management with sine wave curves: application in the United Kingdom

The impact of (adverse) weather is a common cause of delays, legal claims and economic losses in construction projects. Research has recently been carried out aimed at incorporating the effect of weather in project planning; but these studies have focussed on either a narrow set of weather variables, or a very limited range of construction activities or projects. A method for processing a country’s historical weather data into a set of weather delay maps for some representative standard construction activities is proposed. Namely, sine curves are used to associate daily combinations of weather variables to delay and provide coefficients for expected productivity losses. A complete case study comprising the construction of these maps and the associated sine waves for the UK is presented along with an example of their use in building construction planning. Findings of this study indicate that UK weather extends project durations by an average of 21%. However, using climatological data derived from weather observations when planning could lead to average reductions in project durations of 16%, with proportional reductions in indirect and overhead costs.     

The effect of relationship management on project performance in construction

Construction projects often suffer from poor performance in terms of time delays, cost overruns and quality defects. The causes of poor performance have often been analysed. However, few studies have addressed the influence of supply chain relationships on project performance in construction. To fill in this gap, a questionnaire survey is carried out in the UK construction industry to explore the specific characteristics of supply chain relationships in construction and to assess their impact on project performance. In this study, a supply chain relationship is described by key indicators in ten areas: mutual objectives, gain and pain sharing, trust, no-blame culture, joint working, communication, problem solving, risk allocation, performance measurement, and continuous improvement. The analysis reveals that the deterioration of the relationship between project parties may increase the likelihood of poor performance. Poor performance can be effectively reduced by improving some aspects of the relationship. The adoption of supply chain collaboration and partnering helps to solve the performance problems, in which a long-term collaboration is more favourable for performance improvement than a short-term collaboration. In addition to the questionnaire survey, a series of industrial experts are interviewed to provide a deeper insight into the effect of relationship management on project performance.     

浅谈建设工程甲方对工程造价的控制

对工程建设项目造价的复杂性和难以确定性进行了分析,并从工程立项、设计、招投标、施工和竣工五个方面进行了论述研究,以达到工程项目甲方对项目造价控制的效果,从而最大限度地提高建设资金的投资效益。     

Evaluation of queuing systems for knowledge-based simulation of construction processes

During the course of a construction project, there are many situations in which formation of waiting lines or queues is inevitable. The effect of resource delays in queues on the overall project completion time and cost has motivated researchers to employ simulation for analysis of queuing systems in order to identify the best operational strategies to reduce the time wasted in queues. Providing proper and timely input data with high spatial and temporal accuracy for queuing systems simulation enhances the reliability of decisions made based upon the simulation output. Hence, the presented paper describes a methodology for collecting and mining of spatio-temporal data corresponding to the interactions of queue entities to extract computer interpretable knowledge for simulation input modeling. The developed framework was validated using empirical datasets collected from a series of experiments. The extracted relevant knowledge from the queuing system entities was used to update corresponding simulation models.     

A fuzzy logic approach to model delays in construction projects using translational models

The likelihood of a project delay is affected by different factors; thus, there is a pressing need to develop a method that estimates the likelihood of such a delay. In this paper, analysis of potential occurrences of delays, which are classified into procedural, enabling, and triggering causes, is performed using the fuzzy fault-tree analysis method. Subjective judgment expresses causes of delay and their respective degree of effectiveness which are analysed in this study. The fuzzy triangular model and translational models are employed in this study. The severity of the likelihood of the project delay is the result of this analysis. A model was developed to assess the likelihood of the project delay. Evaluation of the model was performed for applicability and adequacy of the model. On average, evaluation performed by independent construction engineers and fuzzy logic experts produced satisfactory results.     

Material and equipment procurement delays in highway projects in Nepal

Delay in the delivery of materials and equipment to construction sites is often thought of as a contributory cause of cost overruns in construction projects in developing countries. A cursory examination of the environment in which projects are executed in developing countries appears to support this thinking. However, there does not seem to have been much research work conducted that investigates whether this is actually the case and also assesses the causes of these delays and magnitude of their impacts on project costs. This research was aimed at firstly ascertaining the occurrence of material and equipment procurement delays in highway projects in Nepal. An assessment of the causes of the delays and the magnitude of their impact on project costs was also made. The survey method was used in conducting this research involving 22 highway projects. The main causes of material and equipment procurement delay were found to be (in rank order) organizational weaknesses, suppliers' defaults, governmental regulations and transportation delays. However, the actual impact of these delays on project costs was found to be on average, only about 0.5% of the total budgeted cost of the projects. Among materials, delays in the supply of aggregates were found to occur most frequently while delays associated with pavers occurred most frequently among equipment.     

浅谈公路施工企业施工过程中的管理与控制

针对公路工程施工管理的重要性,阐述了施工过程现场管理和工程项目成本管理,提出了具体的管理措施,指出施工项目现场管理与项目成本控制是相辅相成的,只有加强施工现场管理,才能控制项目成本,只有达到项目成本控制的目的,加强施工现场管理才有意义。