Developing a Model of Construction Safety Culture

The concept of safety culture is relatively new in the construction industry; however, it is gaining popularity due to its ability to embrace all perceptional, psychological, behavioral, and managerial factors. To address the lack of a verifiable process to analyze construction safety culture, this technical note presents a robust conceptual model that has its roots firmly entrenched in pertinent academic and applied literature. It provides a critical review of the term “safety culture”; along with distinct yet related concepts (i.e., safety climate, behavior-based safety, and safety system). It also compares the proposed model with available safety culture models in order to demonstrate its applicability in construction site environments.     

Construction Safety Risk Mitigation

Construction safety and health management has improved significantly following the Occupational Safety and Health Act of 1970. In response to this legislation, contractors began implementing safety programs to reduce occupational safety and health hazards on construction sites. Researchers recently found that the current process of selecting specific elements for a safety program is informal. This paper describes the results of a recent study designed to determine the relative effectiveness of safety program elements by quantifying their individual ability to mitigate construction safety and health risks. In order to determine the effectiveness of individual safety program elements, the following research activities were performed: (1) an appropriate safety risk classification system was created using an aggregation of relevant literature; (2) highly effective safety program elements were identified in literature; and (3) the ability of each safety program element to mitigate a portion of each of the safety risk classes was quantified using the Delphi method. The results of the research indicate that the most effective safety program elements are upper management support and commitment and strategic subcontractor selection and management and the least effective elements are recordkeeping and accident analyses and emergency response planning. It is expected that the data presented in this paper can be used to strategically select elements for a safety program, target specific safety and health risks, and influence resource allocation when funds are limited.     

Population and Initial Validation of a Formal Model for Construction Safety Risk Management

The transient, unique, and complex nature of construction projects makes safety management exceptionally difficult. Most construction safety efforts are applied in an informal fashion under the premise that simply allocating more resources to safety management will improve site safety. Currently, there is no mechanism by which construction-site safety professionals may formally evaluate safety risk and select safety program elements for implementation. This paper introduces and validates a risk-based safety and health analytical model that can be used to evaluate expected risk given specific worker activities, strategically select highly effective safety program elements for implementation when resources are limited, and quantify resulting risk once the identified safety elements have been implemented. Specifically, the paper has three primary objectives: (1) introduce a risk-based construction safety and health analytical model; (2) validate relevant data used to populate the model; and (3) illustrate the applications of the model in practice. The findings of this research indicate that the values used to populate the model are reliable and that the model has the potential to significantly improve construction safety management.     

Design, Development, and Deployment of a Rapid Universal Safety and Health System for Construction

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.     

Methodology for Integrated Risk Management and Proactive Scheduling of Construction Projects

An integrated methodology is developed for planning construction projects under uncertainty. The methodology relies on a computer supported risk management system that allows for the identification, analysis, and quantification of the major risk factors and the derivation of their probability of occurrence and their impact on the duration of the project activities. Using project management estimates of the marginal cost of activity starting time disruptions, a heuristic procedure is used to develop a stable proactive baseline schedule that is sufficiently protected against the anticipated disruptions that may occur during project execution and that exhibits acceptable makespan performance. We illustrate the application of the methodology on a real life construction project and demonstrate that our proactive scheduler generates baseline schedules that outperform the schedules generated by commercial software packages in terms of robustness and timely project completion probability.     

Owner’s Role in Construction Safety

Despite dramatic improvements in recent decades, the construction industry continues to be one of the industries with the poorest safety records. Recent improvements are due, in part, to the concerted efforts of owners, contractors, subcontractors, and designers. While past safety studies have investigated the roles of contractors, subcontractors, and designers, the owner’s impact on construction safety has not been previously investigated. This paper will present the results of a study on the owner’s role in construction safety. Data were obtained by conducting interviews on large construction projects. The relationship between project safety performance and the owner’s influence was examined, with particular focus on project characteristics, the selection of safe contractors, contractual safety requirements, and the owner’s participation in safety management during project execution. By identifying practices of owners that are associated with good project safety performances, guidance is provided on how owners directly impact safety performance.     

Safety Risk Identification and Assessment for Beijing Olympic Venues Construction

New technologies, new materials, and innovative designs have been extensively adopted in Beijing Olympic venues construction. The extreme requirements for time deadline and competition function expose the venues construction to high risks. These risks would potentially bring negative impacts on the site safety performance. Meanwhile, there is a lack of systematic management for safety risks in China’s construction industry, especially for large projects such as the Beijing Olympic venues construction. This paper identifies and assesses safety risk factors inherent in Beijing Olympic venues construction with the involvement of 27 experienced and highly respected experts from government agencies, the construction industry, and academe through brainstorming, workshop discussions, and questionnaire surveys. The finding reveals that more than half of the critical safety risk factors are from contractors and subcontractors such as: lack of emergency response plan and measures; workers’ unsafe operation, and contractors ignoring safety under schedule pressure. Based on these critical safety risks, a risk register is composed and a model is developed in application of the analytic hierarchy process to assess the status of risks on site safety. The model has been attempted in two Olympic venue projects under construction and the validity has been approved. The risk checklist, register, and assessment model developed in the paper were integrated into the risk management system that has been used for Beijing Olympic venues construction.     

Owner’s Role in Construction Safety: Guidance Model

The practices implemented by owners that were associated with better project safety performances were described in a companion paper. This paper will expand on those research findings and present a model that evaluates the impact of different owner practices on project safety performance. Four indices were established which quantitatively describe the project characteristics, the selection of safe contractors, the contractual safety requirements, and the owner’s participation in safety management. Analysis of variance and linear regression were conducted to evaluate the combined effects of different owner practices on project safety performance as measured by the total recordable injury rate (TRIR). Results show that project safety performances were closely associated with all the indices except the index to describe the selection of safe contractors. The linear regression model explained 42.6% of the total variance of the TRIR. A scorecard to evaluate the owner’s involvement in construction safety was developed to serve as a practical means of conducting an assessment and predicting project safety performance. The owner’s involvement can favorably influence project safety performance by setting safety objectives, selecting safe contractors, and participating in safety management during construction.     

Cognitive Approach to Construction Safety: Task Demand-Capability Model

In the evolution of safety research, the literature identifies three paradigms: normative, error-based, and cognitive engineering. Traditionally, strategies to improve construction safety have been based on the normative paradigm—compliance with prescribed safety rules. However, the normative approach ignores how the characteristics of the production system and team processes influence the work behaviors and the possibility of errors and accidents. These factors are the focus of the cognitive engineering perspective. This study develops a cognitive model of construction safety, which conceptualizes safety as an emergent property of the production system. The model proposes that during a task, the task demands and the applied capabilities determine the potential for errors and accidents. It also proposes that the production practices and the teamwork processes of the crew shape the work situations that the workers face—that is, the task demands and the applied capability. Empirical evidence from recent case studies is discussed. The cognitive perspective shifts the focus of accident prevention from conformance with rules to the issues of task demands and applied capabilities, and the factors affecting them—such as work design, workload, resource allocation, and team processes.     

Fast and Accurate Risk Evaluation for Scheduling Large-Scale Construction Projects

This paper presents the development of a novel probabilistic scheduling model that enables fast and accurate risk evaluation for large-scale construction projects. The model is designed to overcome the limitations of existing probabilistic scheduling methods, including the inaccuracy of the program evaluation and review technique (PERT) and the long computational time of the Monte Carlo simulation method. The model consists of three main modules: PERT model; fast and accurate multivariate normal integral method; and a newly developed approximation method. The new approximation method is designed to focus the risk analysis on the most significant paths in the project network by identifying and removing insignificant paths that are either highly correlated or have high probability of completion time. The performance of the new model is analyzed using an application example. The results of this analysis illustrate that the new model was able to reduce the computational time for a large-scale construction project by more than 94% while keeping the error of its probability estimates to less than 3%, compared with Monte Carlo Simulation methods.     

Risk-Based Safety Impact Assessment Methodology for Underground Construction Projects in Korea

Safety of construction projects may be affected by various factors such as types and scale of projects, construction methods, safety management procedure, climate, site conditions, etc. Among them is the quality of design in relation to safety. Presently, however, designers typically are not involved in construction safety. They are often uncertain of their responsibilities in relation to construction safety and fail to be responsible for avoiding or reducing safety-related risks. In this study, the concept of safety impact assessment to achieve “design-for-safety” in the design phase is introduced. For this purpose, a safety impact assessment model was devised, and a methodology using the risk-based safety impact assessment approach for open-cut type underground construction projects in Korea is suggested. The suggested methodology includes a safety information survey, classification of safety impact factors caused by design and construction, and quantitative estimation of magnitude and frequency of safety impact factors. A checklist which can be easily used for assessing the safety performance of design products is also proposed. A real-world case study on the safety impact assessment of a subway construction project in Korea is also provided in the paper.     

New Method for Measuring the Safety Risk of Construction Activities: Task Demand Assessment

The task demand assessment (TDA) is a new technique for measuring the safety risk of construction activities and analyzing how changes in operation parameters can affect the potential for accidents. TDA is similar to observational ergonomic methods—it does not produce estimates of probabilities of incidents, but it quantifies the “task demand” of actual operations based on characteristics of the activity and independent of the workers’ capabilities. The task demand reflects the difficulty to perform the activity safely. It is based on (1) the exposure to a hazard and (2) the presence and level of observable task demand factors—that is, risk factors that can increase the potential for an accident. The paper presents the findings from the initial implementation of TDA and demonstrates its feasibility and applicability on two different operations: a roofing activity and a concrete paving operation. Furthermore, the paving case illustrates how the TDA method can compare different production scenarios and measure the effect of production variables on the accident potential. The findings indicate that the method can be applied on activities of varying complexity and can account for several risks and task demand factors as required by the user. The selection of task demand factors is a key issue for the validity of the method and requires input from the crew and safety management. The limitations of the methodology and the need for further research are discussed. Overall, TDA provides a tool that can assist researchers and practitioners in the analysis and design of construction operations.     

Can Design Improve Construction Safety?: Assessing the Impact of a Collaborative Safety-in-Design Process

This paper analyzes the impact of a large-scale safety-in-design initiative during the design and construction of a semiconductor manufacturing facility in the Pacific Northwest of the United States. Drawing on multiple data sources including individual interviews, group interviews, construction documentation, and an expert panel involved in the initiative, the writers identify 26 potential design changes on the project and assess the importance of timing, trade contractor involvement, and the type of design change in determining whether a proposed design change was ultimately integrated into the final construction plans. The writers further consider whether adopted design changes would have occurred in the absence of the safety-in-design initiative and whether the accepted design changes ultimately impacted construction site safety on the project. This analysis of a full-scale safety-in-design initiative provides important insights into how injury prevention efforts in the construction industry can begin upstream by involving designers, engineers, and trade contractors in preconstruction processes.     

Non-Unit-Based Planning and Scheduling of Repetitive Construction Projects

Repetitive scheduling methods are more effective than traditional critical path methods in the planning and scheduling of repetitive construction projects. Nevertheless, almost all the repetitive scheduling methods developed so far have been based on the premise that a repetitive project is comprised of many identical production units. In this research a non-unit-based algorithm for the planning and scheduling of repetitive projects is developed. Instead of repetitive production units, repetitive or similar activity groups are identified and employed for scheduling. The algorithm takes into consideration: (1) the logical relationship of activity groups in a repetitive project; (2) the usage of various resource crews in an activity group; (3) the maintaining of resource continuity; and (4) the time and cost for the routing of resource crews. A sample case study and a case study of a sewer system project are conducted to validate the algorithm, as well as to demonstrate its application. Results and findings are reported.     

Psychosocial Factors and Musculoskeletal Disorders in the Construction Industry

Musculoskeletal disorders (MSDs) constitute more than half of the total injuries and illnesses within the construction industry. The aim of this study was to assess the prevalence of MSD among construction workers and identify the psychosocial and physical risk factors associated with their occurrence using an on-site survey instrument. One hundred forty seven construction workers (representing three trades) participated in the study. The 1-year prevalence of MSD was high with 61.2% reporting severe symptoms and 39.7% having some functional impairment due to MSD. Physical task requirement was the most important factor associated with MSD reflecting the physical nature of construction work. Economic and performance factors were the most stressful psychosocial factors reported and significantly increased the risk of reporting MSD. The findings of this research underscore the independent role that psychosocial factors play in the health and safety of construction workers. Understanding this role is imperative for practitioners and academics alike in the quest to make construction a safer work environment for all workers.     

Tradesmen Involvement in Health and Safety

Craftsmen performing construction work are in the best position to determine how a job should be performed safely. They should be involved in planning the safe execution of the work. Involvement will be a function of opportunity, capability, and motivation. A survey of contractor management personnel and craftsmen was conducted to assess their perceptions of these variables. A simulated planning exercise was conducted to assess craftsmen’s capabilities, in terms of knowledge, of construction tasks and risks. Craftsmen were found to be capable, but inexperienced in reducing their knowledge to writing. Questioning uncovered the depth of their knowledge. Craftsmen perceive themselves as capable and motivated and seek the opportunity to be involved in planning for health and safety.     

Viability of Designing for Construction Worker Safety

Designing for construction safety entails consideration of the safety of construction workers in the design of a project. Research studies have identified the design aspect of projects as being a significant contributing factor to construction site accidents. Designing to eliminate or avoid hazards prior to exposure on the jobsite is also listed as the top priority in the hierarchy of controls common to the safety and health professions. Widespread implementation of the concept in the United States by engineering and architecture firms, however, is lacking due to perceived industry and project barriers. Given its absence from standard design practice, a question arises as to the viability of designing for safety as an intervention in the construction industry. This paper presents a pilot study that was conducted to investigate the practice of addressing construction worker safety when designing a project and to determine the feasibility and practicality of such an intervention. Through interviews of architects and engineers, the study found that a large percentage of design professionals are interested and willing to implement the concept in practice. Among the perceived impacts of implementation, project cost and schedule were mentioned most often along with limitations being placed on design creativity. The results of the pilot study indicate that designing for safety is a viable intervention in construction. The factors that impact the consideration of safety in the design of a project do not entirely prohibit its implementation or make its implementation extremely impractical and therefore not feasible. Additionally, the outcomes of implementation provide sufficient motivation to implement the concept in practice. The paper describes the key changes needed for implementation of the concept in practice which include: a change in designer mindset toward safety; establishment of a motivational force to promote designing for safety; increase designer knowledge of the concept; incorporate construction safety knowledge in the design phase; utilize designers knowledgeable about design-for-safety modifications; make design for safety tools and guidelines available for use and reference; and mitigate designer liability exposure.     

Safety Hazard Identification on Construction Projects

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.