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Factors influencing management of construction and demolition (C&D) waste within the Iranian context have yet to be investigated. The purpose of this paper is to define and address this knowledge gap, through development of a model to map the associations among the primary factors affecting C&D waste at project, industry and national levels.

A conceptual model is developed based on synthesising the findings of available studies on factors affecting C&D waste with a focus on developing countries. For collecting data, the study drew upon a questionnaire survey of 103 Iranian construction practitioners. The strength and significance of associations among these factors to modify and validate the model were assessed using the structural equation modelling-partial least squares approach.

Major factors affecting C&D waste management and their level of importance were identified at project, industry and national levels. Results clearly showed that the government should review regulations pertaining to C&D waste management and make sure they are implemented properly. The “polluter pays principle” is a useful guide in devising effective policies and regulations for the Iranian context.

This study contributes to the field through presenting the first major study on C&D waste management in Iran. The study provides a picture of C&D waste management status quo in Iran and encapsulates the factors affecting C&D waste management in the Iranian context at different levels within an integrated model. The findings have practical implications for policy makers and construction practitioners in Iran, similar developing economies and foreign firms planning to operate in Iran.

The purpose of this paper is twofold. First, it aims to highlight the main factors and items affecting the productivity of construction projects, based on the perceptions of CEOs in construction companies in Iran. Second, the study compares the elicited CEOs’ perceptions against the findings of studies based on the views of such as project managers, middle managers and employees in other levels.

The study drew upon literature on construction work to develop a conceptual model. Further, a total of 60 CEOs from road construction companies were surveyed using a five-point Likert scale questionnaire to generate the data. The collated data were categorised and ranked according to the CEOs perceived level of importance using the relative importance index.

The findings highlight the main factors and items affecting labour productivity in construction projects in Iran as perceived by CEOs, which are mainly of human resources management nature and could be attributed to motivation and managerial policy aspects. The study also recognises that factors associated with the working environment particularly safety and health are perceived as insignificant by Iranian CEOs which could be a concern for the Iranian construction industry. The discussions shed some light on the discrepancies between the perceptions of CEOs and previous studies in regards to major determinants of productivity in the construction context.

This study is the first study aiming at discussing the perceptions of CEOs of construction companies active in construction projects in Iran. As such, the study highlights the standpoint of the main decision makers in construction companies in regards to labour productivity in the construction sector. Thus, the key contribution of the present study is providing insight into the perceptions of CEOs, who play the most vital role in strategic development of construction companies whereas previous studies have mostly focused on project or middle managers having a lower influence in determining the strategic plans of companies.

Cost overruns have been identified as the most significant challenge for construction sector stakeholders. Like many developing countries, the Iranian construction industry suffers from poor cost performance. So, the current research aims to investigate the causes of cost overrun in Iranian construction projects. This paper also reviews the findings of similar studies conducted in several Asian countries.

This paper includes a literature review and a quantitative method with a questionnaire survey. The review is limited to the studies investigating the causes of cost overrun in an Asian country in the last decade. Moreover, the current research was conducted through a questionnaire prepared based on 43 common factors identified through the literature review. The required data were gathered from the representatives involved in handling construction activities in Iran. The collected data were analyzed based on relative importance index (RII), using the SPSS software package.

The results showed that poor site management, improper planning, fluctuation of prices of materials, lack of experience, and poor economic condition are the critical reasons for cost overrun in Iranian construction projects. The findings also indicated that among the studies conducted in Asian countries, the first three factors have the highest frequency.

This paper highlighted most studies concerning the cost overrun factors in construction projects in different Asian countries in recent years. Up-to-date knowledge helps to understand the complexity of this field in various periods and therefore minimizes the risk of cost overrun. This research can also be used as a benchmark for further studies to clarify similar issues in other developing countries.

Building upon the results of a critical review of previous studies, the purpose of this paper is to present a framework to enhance the reliability of the theoretical model for international benchmarking of labour productivity (TMIBLP) method for construction project activities. The next part of the paper presents the results of implementing the proposed framework for construction activities in the Iranian construction industry.

This paper draws upon a critical review of the literature to highlight the drawbacks of the previous studies concerning implementing TMIBLP within the construction industry. Identifying these shortcomings, the authors propose a framework for construction projects, which presents the procedure for deploying TMIBLP for construction activities in a reliable manner. The final section of the paper demonstrates the empirical implementation of the proposed framework within the Iranian construction industry.

The primary contributions of the paper include: identifying the drawbacks of previous studies within the construction context, the framework that would lead construction managers towards more reliable implementation of benchmarking for construction projects, and determining the baseline of erecting steel structures in a developing country.

A practical implementation of the TMIBLP method was presented to address the lack of research in Iran and to show the feasibility of using the framework developed. The authors investigated the daily labour productivity for the activity of structural steel erection for six projects in Tehran in order to determine the values of the baseline productivity for each project. Accordingly, the disruption index, performance ratio and project management index as the project benchmarks were calculated for all six projects.

Underlining the necessity of implementing methods such as TMIBLP, this study outlines the outcomes of the first study on the benchmarking of construction activities deploying the proposed framework and using the data on erecting steel structures from six construction projects in Iran. The discussions provide guidelines for construction project managers regarding benchmarking labour productivity. The paper concludes with suggestions for future research opportunities.

The barriers to integrating sustainable practices into construction project management require extensive resource allocations to resolve. Within developing countries such as Iran (where resources are scarce), remedial strategies adopted must prioritise tackling those barriers that can be expected to yield maximum return on investment. The candidate barriers are many, and this paper aims to identify a hierarchy of barriers, providing a priority list of remedial targets.

A mixed philosophical stance of interpretivism and post-positivism is adopted within a deductive approach and survey strategy. A list of 30 known barriers are identified from extant literature and used to formulate a questionnaire data collection instrument administered within the Iranian construction industry. Data collected from 176 practitioners are analysed using the relative importance index and Mann–Whitney U test to compare groups based on the participants' demographic variables.

The findings challenge the common assumption that items related to market and workforce experience are major inhibitors of change. That is, economics and regulatory dependent barriers have a higher impact on the failure of a shift to sustainable practices in Iran. The most influential barriers to incorporating sustainability in construction projects are: (1) lack of understanding of the potential benefits; (2) insufficient cooperation among practitioners, research institutions and environmental organisations; and (3) a lack of a systematic approach to pursuing sustainability goals. No significant associations are detected between the affiliation of the respondents and their attitude towards the issue. Thus, a generalised approach can be applied to a broader range of organisations and construction projects in Iran.

While studies on sustainability impediments at the firm or project level are ubiquitous within literature, this research identifies that the most significant barriers to sustainable project management in Iran, as an underexplored context, are those experienced at the economic and institutional level. Moreover, this novel research presents important insights into the potential effects of participants' demographic profiles on their view of the importance of identified barriers.

Because the construction industry is one of the largest waste producers, understanding the primary reasons for waste production is essential. The goal of this study is to identify the major causes of waste production over the project life cycle in Iran's construction industry and to propose effective solutions based on modern technologies like BIM.

After identifying the primary causes of construction and demolition waste production through interviews and literature analysis, solutions based on building information modeling (BIM) were provided. Then, using questionnaires and exploratory factor analysis (EFA), the areas impacting waste reduction were found.

The findings suggest that “prefabrication” is the best approach for improving time and quality, while “detection and prediction of errors in the design and construction phases” is the most cost-effective technique for addressing cost and environmental issues.

Cost, time, quality and environmental concerns may all be influenced by effective waste management throughout the project life cycle. Furthermore, utilizing state-of-the-art technologies has far-reaching implications for reducing material waste, resulting in more environmental-friendly construction.

The purpose of this paper is to reveal the main causes of delays in the projects are from the client (relative importance index (RII)=0.716), labor and equipment (RII=0.701) and contractor (RII=0.698). Hence determining the contractual responsibility of delay is the most likely source of dispute in construction projects and many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule. Therefore, authors try to investigate all process-based techniques of delay claims and evaluated and conformed them with principles by Society of Construction Law (SCL) protocol and Association for the Advancement of Cost Engineering International (AACEI) in order to choose the best techniques based on the specific circumstances of each project.

This section is divided into two distinct parts: refers to the methods used to assess the perceptions of clients, consultants, and contractors on the relative importance of causes of delay in construction industry; and refers to advantages and disadvantages of various techniques used to analyze delays and their conform with SCL protocol. A questionnaire was developed to assess the perceptions of clients, consultants, and contractors on the relative importance of causes of delay in Iranian construction industry. The respondents were asked to indicate their response category on 78 well-recognized construction delay factors identified by authors.

In total, 78 causes of delay were identified through research. The identified causes are combined into seven groups. The field survey included 58 contractors, 55 consultants, and 62 client. Data collected were analyzed by RII and Statistical Package for Social Sciences (SPSS). The authors identified main causes of delay and ten most important causes, according to Table AII, from the perspective of three major groups of participants (clients, consultants and contractors). The ranking of categories of causes of delay, according to Table I, were: client-related causes (RII=0.716); labor and equipment category causes (RII=0.701); contractor-related causes (RII=0.698); material-related causes (RII=0.690); design-related causes (RII=0.666); external causes (RII=0.662); and consultant-related causes (RII=0.662). But according to the discussions and given that determining the contractual responsibility of delay is the most likely source of dispute in construction industry and many techniques have been used in the courts to demonstrate the criticalities of a delay event on the project schedule.

All process-based techniques of delay analysis have been present in this paper and categorized in 11 groups. In order to understand the advantages and disadvantages of them by clients, contractor and consultant, a thorough review conducted to reveal the nature of techniques. In the next step, given that selecting the most appropriate technique based on constraints and specific conditions of each project is one of the most important steps to carry out a successful delay analysis. The authors conformed, all process-based techniques of delay analysis, by SCL protocol and AACEI principles. Finally, the result of this match was brought in order to choose the best technique based on the specific circumstances of each project.

This paper aims to model different causal relations among factors interacting with labour productivity in order to recognize the most important factors influencing and influenced by it.

Top 60 factors affecting labour productivity were determined and grouped into 5 major groups by reviewing previous research and interviewing relevant experts. The interactions of factors were modelled using system dynamics (SD) approach. The resulting causal loop diagrams obtained from SD were then applied for identifying the most crucial factors influencing and influenced by labour productivity through the decision-making trial and evaluation laboratory (DEMATEL) method. The impact of factors on each other was finally determined based on the opinions of 63 experts selected from the Iranian construction industry.

The results indicated that factors such as fatigue, lack of labour motivation and lack of skill are the most influencing, and factors such as schedule delay and inflation in the cost of execution are the most influenced by labour productivity. In the end, a set of recommendations to improve construction labour productivity was also presented.

The main contribution of the study is proposing a novel method which is capable of providing insights into how causes and effects of construction labour productivity are interrelated. Furthermore, the proposed method makes this study distinct from previous research in the light of prioritizing factors and offering recommendations according to the interrelationships among factors.

The purpose of this study is to compare the trend of academic project management research in Iran and the World in five-year periods with a text mining approach and TF–IDF method.

The research population consists of 1205 theses presented between 2000 and 2019 in Iranian universities. The central library website of the mentioned universities was used for data collection, and the text mining approach with the TF–IDF method was used for data analysis.

The remarkable results of this study include: Concrete structures are the most frequent among structural systems, Risk Management is the most frequent among PMBOK Knowledge Areas, Design-build (DB) system is the most frequent among Project Delivery Systems, Engineering, procurement and construction (EPC) is the most frequent among DB Project Delivery Systems, Financial Management is the most frequent among specialized construction knowledge areas, Soft Skills is the most frequent among Global Trends, Contracting Companies is the most frequent among Project Parties, Construction Projects is the most frequent among Project Areas, Power Plant and Refinery is the most frequent among Project Subjects, Optimization is the most frequent among Problem-Solving Approaches, Fuzzy Logic is the most frequent among Novel Algorithms and Motivation is the most frequent among Soft Skills.

The innovative aspect of this research is that for the first time, text mining has been used to analyze academic research on project and construction management, and also for the first time, academic research on construction industry in Iran has been compared with global research.

The purpose of this paper is to develop a model for complex interconnected structure of various factors interacting with delay in order to identify the most important factors influencing and influenced by delay based on their interrelations.

Reviewing literature and interviewing with local experts selected from the Iranian construction industry, top 58 delay factors were identified and categorized into six major groups. The interrelations among these factors were, then, modeled using the system dynamics (SD) approach. The resulting causal loop diagrams obtained from SD were used subsequently for identifying the most significant factors influencing and influenced by delay through the Decision Making Trial and Evaluation Laboratory (DEMATEL) method. The impact of factors on each other was finally determined based on the opinions of 63 experts selected from the Iranian community of consultants, contractors, and clients.

According to the analysis, eight out of the 58 factors were identified as the most influencing factors on delay, and nine factors were found to be the most influenced factors by delay in the field of delay analysis. The study also concluded that factors related to labors are the most important and influential factors. In addition, factors related to client were the most influencing factors and external-related factors were the least important ones. At the end, some recommendations to reduce variation of delay in the construction projects are presented as well.

Considering the interconnected structure of the factors, the paper identifies the most important factors interacting with time delay in construction projects.