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1.
Theft and vandalism on construction sites in the commercial construction industry is a problem that can affect productivity and drain profits. To explore the impact of theft and vandalism in the commercial construction industry, a survey was sent to commercial construction firms to gather information by which the magnitude of the problem of theft and vandalism could be estimated; and to determine what techniques have been successfully used to deter thieves and vandals. The responses were analyzed and several conclusions were developed. Firms engaging in all types of projects are susceptible to theft and vandalism. Theft is more costly to large sized firms ($100 million and over in annual volume of construction work) than smaller firms, but vandalism is more costly for smaller firms. This occurs despite the fact that larger firms use a greater number of measures to combat theft and vandalism on their construction sites. The results should be of particular interest to construction firms that want to reduce the number of theft and vandalism incidents.  相似文献   

2.
This paper presents information by which to measure safety management performance on construction sites. In China, the conventional construction safety benchmarking approach is to assess safety performance by evaluating the physical safety conditions on site as well as the accident records, while no attention has been paid to the management factors that influence site safety. This paper is to identify the key factors that influence safety management and to develop a method for measuring safety management performance on construction sites. Based on the survey and interview data collected on safety management factors in 82 construction projects in China, the safety management index as a means to evaluate real-time safety management performance by measuring key management factors was developed. The quantified factors were compared with the commonly accepted physical safety performance index, which was derived from inspection records of physical safety conditions, accident rates, and the satisfaction of the project management team. Multifactor linear regression was conducted and the result indicates that safety management performance on site is closely related to organizational factors, economic factors, and factors related to the relationship between management and labor on site. Based on this benchmarking study, a practical safety assessment method was developed and then implemented on six construction projects. The results show that this method can be an effective tool to evaluate safety management on construction projects.  相似文献   

3.
Safety climate can benefit contractors, specialty contractors, and owners of industries by providing them with the knowledge of attitudes and perceptions that can help to consistently achieve better safety performance. The objective of this research was to determine safety climate that would enhance safety culture and positively impact perceived safety performance on construction projects. A safety climate questionnaire survey was conducted on the construction sites of a leading construction company and its subcontractors in Hong Kong. Approximately, 1,500 hard copy questionnaires were distributed and the response rate was excellent, resulting in 1,120 valid questionnaires being collected from 22 construction projects. By means of factor analysis, two underlying safety climate factors were extracted, accounting for 43.9% of the total variance. Multiple regression analysis confirmed that these climate factors, “management commitment and employee involvement” and “inappropriate safety procedure and work practices” were significant predictors of workers’ perceptions of safety performance. The findings indicated that the relationship between perceived safety performance and “inappropriate safety procedure and work practices” was inversely correlated. The results suggest that safety climate can be used as an effective measure of assessing and improving site safety for projects under construction. The findings of this study and the methodology might be useful for research at other construction sites in other regions and countries. This work provides useful information for project managers and safety practitioners who desire to improve safety climate and safety performance on construction sites.  相似文献   

4.
The competitive bidding system has been to blame for abnormally low bids, which are considered as one of the main causes of poor project quality. Previous studies have regarded the pricing of bidders as an optimum decision based on contractor’s cost and market competition level. However, the sell to produce characteristic of construction projects may induce contractors to offer a low bid and then make up the amount initially sacrificed from beyond-contractual reward (BCR) gained through cutting corners and claims. System dynamics was adopted in this study to develop a contractor’s pricing model with consideration of the dimensions of cost, market competition, and BCR. The model was then examined by statistical analysis of data collected from 44 highway projects in Taiwan. It was found that the equilibrium market price is significantly associated with BCR, which is assumed to be determined by the strictness of the owner’s construction management, including both soundness of contract and tightness in construction supervision. Research results suggest that contractors divide the market into different segments according to the owner’s strictness of construction management and the equilibrium price level of each market segment varies. The price level for projects with a strict owner is remarkably higher than for those with relatively less strict owners. Improvement in the construction management system of projects is crucial to lower the possibility that contractors gain BCR and do opportunistic bidding, and to further enhance project quality.  相似文献   

5.
Buffers of material stockpile (inventory) are formed at the work level in construction to help manage production. The size of material stockpiles often has an important bearing on construction project performance. In construction projects, where conditions are often uncertain and variable, some have suggested that buffers be sized and located according to the conditions. New management thinking like lean construction and theory of constraints suggests that the size of buffers needs to be managed carefully, because when oversized, buffers are wasteful, impede workflow, and hinder performance. Research has shown that project variability can be affected with the careful deployment of buffers but has not really evaluated the impact on construction labor performance. This paper reports an exploratory analysis of the relationship between inventory (buffers) and construction labor performance with data collected from three commercial projects in Brazil. In this study, the size of the buffer between rebar fabrication and installation in the construction of a structural system is compared to the labor performance of the fabrication and installation crews. The results show that some buffer helps achieve the best labor performance in the construction operations studied.  相似文献   

6.
Rework has been identified as a major contributor to cost and schedule overrun in construction projects. Previous studies that have examined rework are based on a limited data sets and thus eschew generalizations being made about the key determinants. Using data from 260 completed building (n = 147) and civil engineering (n = 113) projects, path analysis is used to develop a structural model of the most significant causes of rework. The model revealed that the paths of client-directed changes, site management and subcontractors, and project communication were statistically significant contributors to rework costs. The analysis confirmed that the lack of attention to quality management resulted in higher rework costs being incurred in the projects sampled. The analysis also revealed that there were no significant differences between building and civil engineering projects in terms of the direct and indirect cost of rework experienced, and the effectiveness of the project management practices implemented. Considering the findings, it is suggested that generic strategies for reducing the incidence rework in construction and civil engineering projects can be developed.  相似文献   

7.
Construction incidents are essentially random events because they have a probabilistic component that causes their occurrence to be indeterministic. Thus, as with most random events, one of the best ways to understand and analyze construction incidents is to apply statistical methods and tools. Consequently, this paper presents a statistical framework based on the modified loss causation model (MLCM). Even though the MLCM has been used for the framework, the approach can be readily adapted for other incident causation models. The MLCM is separated into two basic components: random and systematic. The random component is represented by a probability density function (PDF), which has parameters influenced by the systematic component of the MLCM, while the systematic component is represented by the situational variables and quality of the safety management system. In particular, this paper proposes that the PDF can be represented by the Poisson distribution. Besides being a convenient and simple distribution that can be easily used in applications, the Poisson distribution had been used in various industries to model random failures or incidents. The differences in contexts and the undesirable effects of adopting an unrepresentative distribution will require formal analysis to determine the suitability of the Poisson distribution in modeling the random component of construction incident occurrence. Incident records for 14 major projects were used in the analysis. Hypothesis testing using the chi-square goodness-of-fit and dispersion tests shows that the incident occurrences can be modeled as a Poisson process characterized by some mean arrival rate. The paper also presents some applications of the proposed Poisson model to improve construction safety management, focusing on two specific concepts: the Bayesian approach and the partitioned Poisson.  相似文献   

8.
Rapid construction projects and processes will become increasingly important as customers demand better project management performance and globally, as countries plan for and respond to the aftermath of natural and/or unnatural disasters. For use in expedited projects (as well as traditional projects), a rapid universal safety and health system (RUSH) was designed, developed, deployed, and evaluated. For its inaugural application, the RUSH was applied to a 106-hour construction project. Results from an initial application included a safe build in approximately 5?days without recordable incidents. More importantly, lessons were learned by a multidisciplinary team of researchers who observed safety 24/5 for the life of the project. Lessons learned and recommendations for future research are provided as a result of this experience.  相似文献   

9.
10.
Since their first successful implementation in 1975, dispute review boards (DRBs) gained popularity as a standing neutral alternative dispute resolution (ADR) technique, and were implemented on a number of high profile construction projects in the United States and worldwide. The purpose of this study is to present a review, trend analysis, and classification of U.S. construction projects that had DRBs for the period of 1975–2007. Thus, a total of 1,042 U.S. construction projects that had DRB as part of their contract provisions are extracted from the Dispute Review Board Foundation database and are analyzed. The results of this study are presented in two major sections. In the first section, results of trend analysis are reported as growth in number of projects with DRB since 1975, as well as the distribution of these projects in terms of construction type (i.e., building, highway, and tunnel), and construction volume category. On the other hand, the second section includes the results of the analysis undertaken to study the mechanics of DRB application in construction projects. In this context, the effectiveness of DRB as a preventive measure against the escalation of conflicts to disputes is first studied. For those projects that had disputes heard by a DRB panel, the data was further analyzed to determine the effectiveness of the DRB as an ADR technique that can help in the resolution of a dispute at the project level without further escalation to arbitration or litigation. The results of the study indicate that DRBs have been successfully implemented in all three construction sectors in the United States. The effectiveness of DRB as a prevention technique was observed on approximately 50% of the 810 projects where no disputes were ever heard through a DRB panel formal hearing. For the remaining 50% of the projects, the effectiveness of DRB as an ADR technique was found to exceed 90% when comparing the number of disputes that were settled due to DRB recommendation to those that were actually heard during a DRB hearing session. Finally, the paper concludes with a set of questions and hypotheses that may be undertaken to explain the recorded observations, and set the way for future research efforts in this area.  相似文献   

11.
Material waste has been recognized as a major problem in the construction industry that has important implications both for the efficiency industry and for the environmental impact of construction projects. Moreover, waste measurement plays an important role in the management of production systems since it is an effective way to assess their performance, allowing areas of potential improvement to be pointed out. This paper describes the main results of two research studies carried out in Brazil that investigated the occurrence of material waste at 74 building sites located in different regions of that country. Some typical figures for the waste of some key construction materials are provided, and the main causes of waste in the sector are discussed. The results indicate that the waste of materials in the Brazilian building industry is fairly high and that a large variability in waste incidence is found across different projects. Most of this waste can be avoided by implementing inexpensive preventive measures, mostly related to managerial improvements.  相似文献   

12.
The prediction of performance time for construction projects is a problem of interest to both researchers and practitioners. This research seeks to gain insight into the significant factors impacting construction duration by developing a regression model. Data were collected for 856 facility projects completed between 1988 and 2004. These data were analyzed using Bromilow’s time-cost (BTC) model (1969) as well as multiple linear regression. The multiple linear regression model was found to provide the most acceptable prediction. As in the BTC model and previous research reported in the literature, a significant correlation was found to exist between cost and duration. However, several other factors were also identified that resulted in significantly lower than average construction durations. These include projects completed within certain management groupings, managed by a certain construction agent, and designed by in-house personnel.  相似文献   

13.
Safety issues have gained vital importance throughout the construction industry. Many construction companies around the world are implementing safety, health, and environmental management systems to reduce injuries, eliminate illness, and to provide a safe work environment in their construction sites. This paper describes an exploratory study of site safety management in construction sites’ environments. It explains a successful, modern safety, health and environmental management system for a leading construction company based in Hong Kong. A typical site-specific safety plan was utilized to provide safety guidance throughout the construction project. A safety management survey was conducted to determine the status of safety in the construction sites. All employees of the company and its subcontractors participated in the survey from 20 construction projects. In total, 1,022 valid records were obtained from the construction sites. The analysis provided useful information on eight aspects of construction safety, including safety policy and standards, safety organization, safety training, inspecting hazardous conditions, personal protection program, plant and equipment, safety promotion, and management behavior. The findings of the survey provide practical knowledge to construction project managers and construction safety practitioners in order to make their sites safer. Insights and discussions are given in this paper.  相似文献   

14.
One of the main problems in the process of design and management of construction projects is obtaining accurate information for preliminary estimates. This information is crucial for the development of integrated systems for construction management because of the relationship between construction input data and subjects such as estimating, cost control, scheduling, resource management, etc. Existing methods for estimating input that originated in industrial engineering are inadequate for the unique conditions of the construction industry. The model described in this paper applies statistical analysis of data from past projects, and enables the user to estimate the data needed for the construction of a new project. The model is based on the following components: Project items and their quantities; inputs needed to produce those items; and factors that affect inputs of a specific project. The model equation was calculated using multiple regression techniques. The paper concludes with a case study of a construction input configuration for a concrete structure.  相似文献   

15.
On-site materials-handling operations are error prone and the errors that occur significantly decrease construction productivity. New technologies and sensing devices can enhance materials-handling management practices on construction job sites. This paper describes a study that aimed to determine the potential benefits of the deployment of global positioning system (GPS) technology within the materials-locating processes on industrial projects. Its main goals were (1) to evaluate the technical feasibility and (2) to quantify the direct benefits in terms of process duration derived from the integration of GPS devices within pipe-locating processes. A field trial was conducted and its results indicated significant time savings. This study also analyzed additional potential benefits derived from the use of GPS in this scenario.  相似文献   

16.
Due to the demand for built products from foreign investors and the growing economy, Vietnam’s construction industry experiences strong growth. While some of the construction projects are successfully executed, others faced difficulties. The aim of this study is to examine the factors that lead to successful outcomes in construction projects in Vietnam. Using the case study research design, three successful projects and another three unsuccessful projects were investigated. Data were collected from face-to-face interviews with several project participants in each project and archival data. The results show that major enablers that lead to project success are foreign experts’ involvement in the project, government officials inspecting the project, and very close supervision when new construction techniques are employed. A factor which leads to poor performance is the lack of accurate data on soil, weather, and traffic conditions. The findings may be useful to construction professionals operating in Vietnam to put in place factors that can lead to good project performance. For foreign practitioners entering Vietnam’s market, the study may assist them in focusing on the more important factors to achieve good project outcomes.  相似文献   

17.
Originating from the West, project management was introduced into China after the country’s economic reforms in the 1980’s and has since spread quickly throughout the whole country, particularly in the construction industry. However, despite the wide adoption of project management practices by construction organizations and the growing recognition of the importance of project management as an enabler of organizational success, empirical studies on project management in the context of the Chinese construction industry have been inadequate. This paper presents the results of an empirical study of six Chinese construction organizations in order to come to a more comprehensive and sophisticated understanding of project management practices in the Chinese construction industry. The findings revealed: (1) a good appreciation of the role of projects and project management and satisfaction with current project management practices; (2) 11 key aspects of project management implementation; (3) 12 resultant value and benefits; and (4) five aspects of the main challenges facing the organizations. Meanwhile, variations in project management practices and the resultant organizational value were identified, first between the three owner- and the three contractor-case study organizations, then between the two construction contractor organizations and the one design contractor organization.  相似文献   

18.
Bridges are principal and vital transportation structures. If risk management is not considered in bridge construction projects, objectives cannot be delivered on time, on budget, or with suitable quality results. Risk data set sizes and experts’ judgments are not usually sufficient for analyzing significant risks in bridge construction projects; moreover, the statistical distributions for risk parameter estimates are usually unknown. Standard parametric statistical techniques cannot provide appropriate solutions for cases with small data sets or unknown distributions. This paper proposes a new hybrid approach by using a nonparametric resampling technique and interval computations for risk analysis, in particular, for bridge construction projects. Bootstrap techniques produce more accurate inferences for comparing parametric techniques and are an alternative when the underlying parametric assumptions are not considered. Increasingly, because of the complexity and uncertainty in decision making at bridge projects, it is easier or more natural to provide interval values for parts or all of decision-making judgments. Furthermore, the goal of reducing standard deviations for both risk probability and risk impact compared with the conventional approach is another conclusion of this paper. The proposed approach is applied to a case in Iran to show the validity of the approach.  相似文献   

19.
This article presents a generic project risk management process that has been particularized for construction projects from the point of view of the owner and the consultant who may be assisting the owner. The process could also be adapted to the needs of other project participants, and many points referred to in the article can be directly applied to them. Any project risk management process must be tailored to the particular circumstances of the project and of the organization undertaking it. First, the article explains a complete or generic project risk management process to be undertaken by organizations with the highest level of risk management maturity in the largest and most complex construction projects. After that, factors influencing possible simplifications of the generic process are identified, and simplifications are proposed for some cases. Then the application to a real project is summarized. As a final validation, a Delphi analysis has been developed to assess the project risk management methodology explained here, and the results are presented.  相似文献   

20.
Hazard identification is fundamental to construction safety management; unidentified hazards present the most unmanageable risks. This paper presents an investigation indicating the current levels of hazard identification on three U.K. construction projects. A maximum of only 6.7% of the method statements analyzed on these projects managed to identify all of the hazards that should have been identified, based upon current knowledge. Maximum hazard identification levels were found to be 0.899 (89.9%) for a construction project within the nuclear industry, 0.728 (72.8%) for a project within the railway industry, and 0.665 (66.5%) for a project within both the railway and general construction industry sector. The results indicate that hazard identification levels are far from ideal. A discussion on the reasons for low hazard identification levels indicates key barriers. This leads to the presentation of an Information Technology (IT) tool for construction project safety management (Total-Safety) and, in particular, a module within Total-Safety designed to help construction personnel develop method statements with improved levels of hazard identification.  相似文献   

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