John A. Gambatese

Qualitative Research: Application of the Delphi Method to CEM Research

Construction engineering and management CEM researchers often rely on alternative research techniques when traditional methods fail. For example, surveys, interviews, and group-brainstorming techniques may not be appropriate for research that involves confounding factors and requires access to sensitive data. In such an environment, the Delphi technique allows researchers to obtain highly reliable data from certified experts through the use of strategically designed surveys. At present, the Delphi method has not seen widespread use in CEM research. This is likely due to variation among studies that implement Delphi in CEM research and ambiguity in literature that provides guidance for the specific parameters associated with the method. Using the guidance in this paper, the reader may: 1 understand the merits, appropriate application, and appropriate procedure of the traditional Delphi process; 2 identify and qualify potential expert panelists according to objective guidelines; 3 select the appropriate parameters of the study such as the number of panelists, number of rounds, type of feedback, and measure of consensus; 4 identify potential biases that may negatively impact the quality of the results; and 5 appropriately structure the surveys and conduct the process in such a way that bias is minimized or eliminated.

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.

Enabling and measuring innovation in the construction industry

Innovation is vital to successful, long-term company performance in the construction industry. Understanding the innovation process, how innovation can be enhanced and how it can be measured are key steps to managing and enhancing innovation. The factors that affect innovation on a project were identified, as well as how these factors can be used to measure the level of innovation on a project, and the practices and processes that encourage and facilitate innovative changes. Case studies of construction projects in the United States revealed three necessary components of innovation: idea generation, opportunity and diffusion. A variety of practices are used to optimize each component including support and commitment from the owner/client and firm upper management, workforce and project team integration and diversity. Applying the practices identified in the research leads to enhanced innovation through better communication among project team members, integration of the design and construction disciplines, more efficient designs, development of unique ways of completing work and sharing of the lessons learned. The end result of innovation will be projects that successfully meet and exceed cost, quality, schedule and safety goals.

The Trajectories of Prevention through Design in Construction

INTRODUCTION Construction Hazards Prevention through Design (CHPtD) is a process in which engineers and architects explicitly consider the safety of construction workers during the design process. Although articles on CHPtD have appeared in top construction journals, the literature has not addressed technical principles underlying CHPtD to help designers better perform CHPtD, to facilitate the development of additional CHPtD tools, and to predict the future path of CHPtD. METHOD This theoretical paper uses the existing literature on CHPtD and current action research associated with several CHPtD workgroups to analyze how CHPtD will likely evolve over the coming decades. RESULTS There are four trajectories along which CHPtD will progress. (a) Designs will increasingly facilitate prefabricated construction; (b) designers will increasingly choose materials and systems that are inherently safer than alternatives; (c) designers will increasingly perform construction engineering; and (d) designers will increasingly apply spatial considerations to reduce worker hazards. IMPACT ON INDUSTRY By understanding how CHPtD may be manifested in the engineering-procurement-construction (EPC) industry, practitioners can better prepare for adopting CHPtD within their organizations and construction and engineering educators can better prepare their graduates to perform CHPtD.

Activity-Based Safety Risk Quantification for Concrete Formwork Construction

Most of safety risk research focuses on high-severity safety risks for large-scale construction processes. Such studies help firms identify the highest risk processes so they may be targeted for improvement. However, few studies quantify safety risk at the activity level or include low-severity, high-frequency risks that some literatures suggest contribute to a large proportion of total risk. This paper presents research that involved the holistic quantification of risks for the activities associated with the construction of concrete formwork. Three major research efforts are discussed: (1) identification of activities required to construct concrete formwork; (2) selection of an appropriate all-inclusive and mutually exclusive risk classification system; and (3) the quantification of the average frequency and severity levels for each risk classification associated with each activity. To identify formwork construction activities, 256 worker-hours of observation were conducted and the resulting activity descriptions were reviewed and validated by industry professionals. Risk classifications appropriate for this study were created by aggregating relevant literature. Finally, the Delphi method was implemented to individually quantify average frequency and severity using scales that define the entire spectrum of possible values. In total, 130 frequency ratings and 130 severity ratings were obtained over three rounds of Delphi surveys. Results indicate that there are 13 major activities required to construct concrete formwork and the highest risk activities are applying form oil, lifting and lowering form components, and accepting materials from a crane. The data presented in this paper can be used to target specific high-risk formwork construction activities for improvement.

Factors that influence the development and diffusion of technical innovations in the construction industry

Some technical innovations diffuse rapidly throughout the construction industry while others take a long time or are never integrated into everyday practice. Understanding the initiation, development, implementation and outcomes of successful technical innovations within the construction industry provides guidance for the improvement of the innovation process. To further this understanding, innovation generating organizations (IGOs) in the construction industry were surveyed and the data were statistically analysed. Two sources were used to identify newly developed products, technologies and management strategies: the Construction Innovation Forum’s NOVA Award website and the Emerging Construction Technologies (ECT) website. A total of 233 innovative products were identified from the two websites. The results showed that there are many statistically significant motivating factors for investment in the initial development of successful technical innovation, barriers and enablers to efficient diffusion and innovation outcomes on construction projects. Additionally, successful development, implementation and diffusion of an innovative product required an average of 38 months, 4700 worker‐hours and

Sustainable Roadway Construction: Energy Consumption and Material Waste Generation of Roadways

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Research issues in Prevention through Design.

Sustainable roadway construction can be defined as the optimal use of natural and man-made resources during the roadway lifecycle causing negligible damage to the environment. Two means of improving the sustainability of roadways are to minimize the amount of energy consumed for their construction and to efficiently use roadway materials to reduce waste. This paper describes two separate studies conducted to estimate the amount of energy consumed and the amount of waste generated in continuously reinforced concrete pavement (CRCP) and asphalt pavement (AC) roadways from extraction of raw materials through the end of construction. For CRCP, energy is primarily consumed during the manufacture of cement and reinforcing steel, while for AC the majority of energy is consumed during asphalt mixing, drying of aggregates, and the production of bitumen. With regard to material waste, most of the waste generated from CRCP roadways occurs during extraction and production of cement and aggregates. For AC, the extraction and production of aggregates produce the majority of waste. The results indicate that the amount of waste generated is greater for CRCP than for AC. The results of the two studies highlight where sustainable design efforts to reduce energy consumption and waste generation can best be directed in the initial phases of a pavements life cycle.

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

Prevention through Design (PtD) research is central to the National Institute for Occupational Safety and Healths (NIOSH) national PtD initiative. Research is needed to support PtD efforts in all of the other three functional areas (Practice, Policy, and Education) and within all eight industry sectors. The PtD concept is new to many industry sectors. An understanding of how the PtD concept can be effectively implemented, and the resulting impacts and outcomes, is lacking in some industries and in need of fine tuning in others. Research will provide the opportunity to explore and gain further understanding of the concept, and evidence to support a national PtD initiative.

Real Options Valuation of Phased Investments in Commercial Energy Retrofits under Building Performance Risks

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.