Kim, Jonghyeob; Han, Sangwon; Hyun, Chang-taek. (2019). Identification and Reduction of Synchronous Replacements in Life-Cycle Cost Analysis of Equipment. Journal Of Management In Engineering, 35(1).
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Abstract
Life-cycle cost analysis (LCCA) is a methodology used to calculate the total cost of a project from initial planning to final disposal. In conventional approaches, LCCA assumes that regular and preventive maintenance will be performed according to each replacement cycle for individual components, and replacement for each component is considered independently. However, because the components of equipment used in buildings are installed systemically, replacements of major components may cause unexpected replacements of dependent minor components. Therefore, it is necessary to identify additional replacements based on the associations among these related replacement components to achieve a more reliable LCCA. In response, this study proposes an LCCA model that comprehensively considers the relationships among the maintenance components. The development of the model involves identifying relationships among components using social network analysis (SNA), arranging individual replacement timings of the components that reflect these relationships, and analyzing the life-cycle cost (LCC) based on the arranged timing. To validate the model, its applicability and effectiveness was illustrated and tested using 19 components of a rainwater reuse system. This study makes a theoretical contribution to the body of knowledge by suggesting concepts of synchronous relationships and replacements based on SNA. In addition, the use of the model proposed in this study enables practitioners to analyze LCCs that reflect synchronous replacements, which allows more reasonable decision-making considering hidden costs in conventional LCC. (C) 2018 American Society of Civil Engineers.
Keywords
Decision Making; Life Cycle Costing; Preventive Maintenance; Synchronous Replacements; Life-cycle Cost Analysis; Lcca Model; Maintenance Components; Social Network Analysis; Painted Surfaces; Decision-making; Prediction; Model; Risk; Maintenance; Replacement; Synchronous Replacement; Synchronous Relationship; Life-cycle Cost Analysis (lcca); Social Network Analysis (sna)
Habibnezhad, Mahmoud; Puckett, Jay; Jebelli, Houtan; Karji, Ali; Fardhosseini, Mohammad Sadra; Asadi, Somayeh. (2020). Neurophysiological Testing for Assessing Construction Workers’ Task Performance at Virtual Height. Automation In Construction, 113.
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Abstract
Falling from heights is the primary cause of death and injuries at construction sites. As loss of balance has a fundamental effect on falling, it is important to understand postural regulation behavior during construction tasks at heights, especially those that require precise focus in an upright standing position (therefore, a dual-task demand on focus). Previous studies examined body sway during a quiet stance and dual tasks to understand latent factors affecting postural balance. Despite the success of these studies in discovering underlying factors, they lack a comprehensive analysis of a task's simultaneous cognitive load, postural sway, and visual depth. To address this limitation, this paper aims to examine construction workers' postural stability and task performance during the execution of visual construction tasks while standing upright on elevated platforms. To that end, two non-intrusive neurophysiological tests, a hand-steadiness task (HST) and a pursuit task (PT), were developed for construction tasks in a virtual environment (VE) as performance-based means to assess the cognitive function of workers at height. Workers' postural stability was measured by recording the mapped position of the Center of Pressure (COP) of the body on a posturography force plate, and the postural sway metrics subsequently calculated. A laboratory experiment was designed to collect postural and task performance data from 18 subjects performing the two batteries of tests in the virtual environment. The results demonstrated a significant decrease in the Root-Mean Square (RMS) of COP along the anterior-posterior axis during the Randomized Pursuit Task (RPT) and maximum body sway of the center of pressure (COP) in the mediolateral direction during both tests. Also, subjects exposed to high elevation predominately exhibit higher accuracy for RPT (P-value = 0.02) and lower accuracy for HST (P-value = 0.05). The results show that the combination of elevation-related visual depth and low-complexity dual tasks impairs task performance due to the elevation-induced visual perturbations and anxiety-driven motor responses. On the other hand, in the absence of visual depth at height, high task complexity surprisingly improves the pursuit tracking performance. As expected, during both tasks, alterations in postural control were manifested in the form of a body sway decrement as a compensatory postural strategy for accomplishing tasks at high elevation.
Keywords
Task Performance; Construction Workers; Test Design; Cognitive Load; Standing Position; Sitting Position; Neurophysiological Test; Postural Stability; Virtual Reality; Workers' Safety At Height; Fall-risk; Reaction-time; Fear; Real; Acrophobia; Balance; Safety
Shang, Luming; Migliaccio, Giovanni C. (2020). Demystifying Progressive Design Build: Implementation Issues and Lessons Learned through Case Study Analysis. Organization Technology And Management In Construction, 12(1), 2095 – 2108.
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Abstract
The design-build (DB) project delivery method has been used for several decades in the US construction market. DB contracts are usually awarded on the basis of a multicriteria evaluation, with price as one of the most salient criteria. To ensure the project's success, an owner usually has to invest enough time and effort during scoping and early design to define a program, scope, and budget, ready for procurement and price generation. However, this process can become a burden for the owner and may lengthen the project development duration. As an alternative to the traditional DB, the progressive design-build (PDB) approach permits the selection of the DB team prior to defining the project program and/or budget. PDB has the advantage of maintaining a single point of accountability and allowing team selection based mainly on qualifications, with a limited consideration of price. Under PDB, the selected team works with the project stakeholders during the early design stage, while helping the owner balance scope and budget. However, the key to the effectiveness of PDB is its provision for the ongoing and complete involvement of the owner in the early design phase. Due to the differences between PDB and the other project delivery methods (e.g., traditional DB), project teams must carefully consider several factors to ensure its successful implementation. The research team conducted a case study of the University of Washington's pilot PDB project to complete the West Campus Utility Plant (WCUP). This paper carefully explores and summarizes the project's entire delivery process (e.g., planning, solicitation, design, and construction), its organizational structures, and the project performance outcomes. The lessons learned from the WCUP project will contribute to best practices for future PDB implementation.
Keywords
Progressive Design Build; Project Delivery Method
Zhang, Zhenyu; Lin, Ken-yu; Lin, Jia-hua. (2021). Factors Affecting Material-Cart Handling in the Roofing Industry: Evidence for Administrative Controls. International Journal Of Environmental Research And Public Health, 18(4).
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Abstract
Material-cart handling can be strenuous and lead to overexertion injuries. The aim of this study is to produce a thorough understanding of how the cart condition, tire type, physical environment-related factors, and load interact to influence the ergonomics and productivity of cart handling. Eighteen roofing carts with different conditions, tires, and loads were tested by one subject on three laboratory tracks: one L-shaped, one with ramps within constrained spaces, and one with obstacles within constrained spaces. A multiple linear regression analysis was performed to quantify the main and interaction effects of the factors of interest on the cart operations. The research findings confirm that using aged carts increases the injury risk by as much as 30.5% and decreases productivity by 35.4%. Our study also highlights the necessity of keeping an open space for cart operation; the travel distance from a cart to a ramp/obstacle should be greater than 61 cm. Finally, the results suggest the at-risk thresholds for different ramp slopes and obstacle heights, and the safe load capacities for the various working circumstances that are common on construction sites. The evidence created in this study can be translated into administrative controls for cart handling to reduce overexertion injuries and enhance performance.
Keywords
Overexertion In Pulling And Pushing; Material Cart Handling; Roof Construction; Ergonomic Risk Factors; Administrative Control
Kim, Yong-Woo; Han, Seungheon; Shin, Sungwon; Choi, Kunhee. (2011). A Case Study of Activity-Based Costing in Allocating Rebar Fabrication Costs to Projects. Construction Management And Economics, 29(5), 449 – 461.
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Abstract
How to improve cost allocation for reinforced steel bar (rebar) is an ongoing topic of debate among construction manufacturers and contractors. Traditionally, many fabrication shops have used a single overhead-cost pool accounting system. However, a new costing method, activity-based costing (ABC), may provide more advantages than the traditional system. In this case study, a single overhead-cost pool system is compared with the ABC method to demonstrate how ABC improves cost allocation and provides other benefits. The case study findings indicate that ABC provides such benefits as (1) accurate manufacturing costs; (2) cost information on processes; and (3) information on cost drivers. This paper also bridges the construction and cost accounting literature. Our study contributes to the construction management literature by offering a different cost allocation method to refine fabrication costs assigned to projects. The findings are expected to serve as a reference for industry professionals who recognize the shortcomings of a traditional single overheadcost pool system and are in need of a more accurate costing system. © 2011 Taylor & Francis.
Keywords
Bridges; Costs; Fabrication; Lakes; Project Management; Rebar; Accounting System; Activity Based Costing; Construction Management; Fabrication Shops; Industry Professionals; Manufacturing Cost; Overhead Costs; Traditional Systems
Kim, Yong-Woo; Azari-N, Rahman; Yi, June-Seong; Bae, Jinwoo. (2013). Environmental Impacts Comparison between On-site vs. Prefabricated Just-in-Time (Prefab-JIT) Rebar Supply in Construction Projects. Journal Of Civil Engineering And Management, 19(5), 647 – 655.
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Abstract
In the on-site rebar delivery system, as the common method of rebar supply in the construction industry, reinforced steel bars are delivered in large batches from supplier's facilities through contractor's warehouse to the construction site. Rebars are then fabricated on-site and installed after assembly. In the new delivery system, called prefabrication Just-In-Time (prefab-JIT) system, the off-site cut and bend along with frequent rebar delivery to the site are applied in order to improve the process and increase its efficiency. The main objective of this paper is to assess and compare the environmental impacts resulting from the air emissions associated with the two rebar delivery systems in a case study construction project. Environmental impact categories of interest include global warming, acidification, eutrophication, and smog formation. A process-based cradle-to-gate life cycle assessment methodology is applied to perform the analysis. The results show that the prefab-JIT rebar delivery system causes less contribution to all mentioned environmental impact categories compared with a traditional on-site delivery system.
Keywords
Environmental Impact Analysis; Comparative Studies; Microfabrication; Construction Industry; Reinforcing Bars; Contractors; Product Life Cycle; Environmental Impacts; Life Cycle; On-site Rebar Delivery System; Prefab-jit; Bars; Contracts; Global Warming; Just-in-time; Prefabricated Construction; Product Life Cycle Management; Project Management; Rebar; Steel; Warehousing; Waste Reduction; Smog Formation; Eutrophication; Acidification; Air Emissions; Prefab-jit System; Construction Site; Contractors Warehouse; Reinforced Steel Bars; Construction Projects; Prefabricated Just-in-time Rebar Supply; Environmental Impacts Comparison; Process-based Cradle-to-gate Life Cycle Assessment Methodology; Energy; Products; Wood
Lee, Namhun; Schaufelberger, John E. (2014). Risk Management Strategies for Privatized Infrastructure Projects: Study of the Build-Operate-Transfer Approach in East Asia and the Pacific. Journal Of Management In Engineering, 30(3).
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Abstract
Private-public partnerships have been adopted for the development of public infrastructure to meet the growing demand for public services. Many Asian countries have used the build-operate-transfer (BOT) approach to develop public infrastructure projects. However, the potential benefits of undertaking a BOT project are accompanied by corresponding risks from the private sector's perspective. The objectives of this study are (1)to identify and discuss major risks inherent in the East Asia and Pacific regions, and (2)to propose risk management strategies for future BOT projects to be successful. This paper reports the results of five case study analyses undertaken to review their primary risks and mitigated methods. In addition, this paper proposes some strategies for future BOT projects. Two main categories of risks were analyzed: general risks and project-specific risks. Risk management strategies were suggested for each category of risk. The main finding of this study indicates that the private sector cannot be the only participant in risk management. The host government's active support is the most essential factor for the profitability and economic viability of a BOT project in the East Asia and Pacific regions.
Keywords
Organisational Aspects; Project Management; Public Administration; Public Utilities; Risk Management; Structural Engineering; Risk Management Strategies; Privatized Infrastructure Projects; Build-operate-transfer Approach; East Asia; Private-public Partnerships; Public Services; Asian Countries; Public Infrastructure Projects; Pacific Regions; Future Bot Projects; Project-specific Risks; General Risks; Build-operate-transfer; Privatized Infrastructure
Abdirad, Hamid; Dossick, Carrie S. (2016). BIM Curriculum Design in Architecture, Engineering, and Construction Education: A Systematic Review. Journal Of Information Technology In Construction, 21, 250 – 271.
Abstract
In the past several years, Building Information Modeling (BIM) adoption has grown significantly in the architecture, engineering, and construction (AEC) industry. In response to this trend, the industry and academia realized that BIM education in university curricula is an important requirement for satisfying educational demands of the industry, and a notable body of research has reported strategies AEC programs implemented to incorporate BIM in their curricula. However, no study has comprehensively reviewed and synthesized the research on sfrategies adopted by educators. To bridge this gap in the literature, this paper presents a systematic review of research on BIM curriculum design in AEC education. The authors report on the trends of research on BIM curriculum design (e.g. methods, timelines, and contexts) as well as a synthesis of implemented pedagogical strategies with detailed discussions on their implications and effectiveness across different studies and contexts. These strategies address a variety of important pedagogical issues such as enrolment of students, optional or required BIM use, important competencies and skills, tutoring methods, industry engagement, designing assignments, and assessment methods and criteria. This synthesis shows that designing pedagogical sfrategies for BIM education is complex and challenging, and AEC programs need to make trade-offs between advantages and disadvantages associated with these strategies. The results also highlight the need for more diverse research designs and settings to bridge the gaps identified in BIM curriculum research to date. Finally, the authors present a literature-based framework of BIM curriculum design sfrategies as well as a set of recommendations that can be used BIM educators and researchers as a guide for designing or assessing their BIM curricula in future research.
Keywords
Bridges; Curricula; Economic And Social Effects; Education; Information Theory; Personnel Training; Reviews; Students; Architecture; Engineering; And Constructions; Building Information Model; Bim; Curriculum Designs; Pedagogical Issues; Pedagogical Strategies; Research Designs; Systematic Review; University Curricula; Industry; Management; Building Information Modeling; Training; Curriculum; Review
Ochsner, Jeffrey Karl. (2016). Seattle, the Pacific Basin, and the Sources of Regional Modernism. Fabrications-the Journal Of The Society Of Architectural Historians Australia And New Zealand, 26(3), 312 – 336.
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Abstract
The emergence of mid-twentieth-century architecture that was both modern and regional in Seattle and nearby areas of Washington State presents a singular case study demonstrating an array of influences from Asia and Latin America as well as the Pacific Coast of the United States. This network of influences is evidence of the complexity of a dissemination that gained momentum in the 1930s as the modern movement began to spread globally, as identified by historian William J. R. Curtis. Although awareness of distant sources primarily influenced design vocabularies from the 1930s to the 1950s in the Pacific Northwest, by the early 1960s, as Seattle architects and landscape architects began to travel to Japan, they developed a much deeper understanding from a broader collection of sites, and this, in turn, shaped surprisingly varied local responses from Rich Haag's ideas of non-striving design to Victor Steinbrueck's increasing interest in Pike Place Market. Untangling the array of Pacific Basin influences that helped shape mid-twentieth-century design in Seattle provides one demonstration of the validity of considering the Pacific as an interdependent region. Thus, Seattle offers a foundational case study towards the future project of writing an encompassing account of the interconnected architectural history of the Pacific Basin.
Song, Jiule; Migliaccio, Giovanni C.; Wang, Guangbin; Lu, Hao. (2017). Exploring the Influence of System Quality, Information Quality, and External Service on BIM User Satisfaction. Journal Of Management In Engineering, 33(6).
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Abstract
Over the past decade, architecture, engineering and construction (AEC) companies around the world implemented building information modeling (BIM) to enhance their firms' competitiveness and readjust their business processes. Although substantial efforts have been made to implement BIM, previous research highlighted that implementation of BIM tools has not always resulted in satisfaction by users. Grounded in the literature on information systems and enterprise resource planning user satisfaction, this study tries to evaluate the success of BIM in terms of user satisfaction while controlling for the mediating effect of top-management support. The effects of four factors (i.e., system quality, information quality, external service, and top-management support) on BIM user satisfaction in AEC industries were examined through a survey of BIM users from China. Survey responses were analyzed with the partial least-squares method. The major contribution of this work lies in the findings that information quality, external service, and top-management support have a significant influence on BIM user satisfaction, and system quality did not have a significant influence on BIM user satisfaction. Moreover, top-management support acts as a mediating factor between external service and BIM user satisfaction. (C) 2017 American Society of Civil Engineers.
Keywords
Computing Satisfaction; Perceived Usefulness; Erp Systems; Success; Model; Performance; Technology; Acceptance; Tool; Determinants; Bim User Satisfaction; System Quality; Information Quality; External Services; Top-management Support