Kim, Yong-Woo; Ballard, Glenn. (2010). Management Thinking in the Earned Value Method System and the Last Planner System. Journal Of Management In Engineering, 26(4), 223 – 228.
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Abstract
Management theory has been neglected in the construction industry, which has rather focused on best practices. This paper investigates the theories implicit in two prevalent project control systems: the earned value method (EVM) and the last planner system (LPS). The study introduces two fundamental and competing conceptualizations of management: managing by means (MBM) and managing by results (MBR). The EVM is found to be based on MBR. However, project control based on MBR is argued to be inappropriate for managing at the operational level where tasks are highly interdependent. The LPS is found to be based on the MBM view. The empirical evidence from literature and case study suggested that the MBM view is more appropriate to manage works when it is applied to the operation level where each task is highly interdependent.
Keywords
Last Planner System (lps); Management Thinking; Performance Measures; Project Control
Kim, Taehoon; Kim, Yong-Woo; Cho, Hunhee. (2020). Dynamic Production Scheduling Model Under Due Date Uncertainty in Precast Concrete Construction. Journal Of Cleaner Production, 257.
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Abstract
Precast concrete structures (PCs) are widely used in the construction industry to reduce project delivery times and improve quality. On-time delivery of PCs is critical for successful project completion because the processes involving precast concrete are the critical paths in most cases. However, existing models for scheduling PC production are not adequate for use in dynamic environments where construction projects have uncertain construction schedules because of various reasons such as poor labor productivity, inadequate equipment, and poor weather. This research proposes a dynamic model for PC production scheduling by adopting a discrete-time simulation method to respond to due date changes in real time and by using a new dispatching rule that considers the uncertainty of the due dates to minimize tardiness. The model is validated by simulation experiments based on various scenarios with different levels of tightness and due date uncertainty. The results of this research will contribute to construction project productivity with a reliable and economic precast concrete supply chain. (C) 2020 Elsevier Ltd. All rights reserved.
Keywords
Multiple Production; Demand Variability; Supply Chain; Shop; Management; Minimize; Lines; Precast Concrete Production; Dynamic Simulation; Uncertainty; Production Scheduling; Dispatching Rule
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; Rhee, Byong-Duk. (2020). The Impact of Empowering Front-Line Managers on Planning Reliability and Project Schedule Performance. Journal Of Management In Engineering, 36(3).
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Abstract
This study applies empowerment theory to production planning at the level of frontline managers in a construction project. Using structural equation modeling, we investigate how empowering frontline managers impacts their planning performance. In contrast to prior studies, we find that although psychological empowerment of frontline managers has no direct effect on their production planning reliability or scheduling performance, it has an indirect effect on planning reliability and scheduling performance, as long as the organization supports the empowerment structurally during production planning. This implies that a project manager should provide frontline managers at the operational level with proper formal and informal authority over workflow development, shielding, and resource allocation when planning production in order to enhance job performance through psychological empowerment. This study contributes to the body of knowledge on construction management by exploring the impact of psychological and structural empowerment of frontline managers on their performance of production planning reliability and scheduling performance.
Keywords
Psychological Empowerment; Work; Model; Variables; System; Job; Planning Reliability; Production Planning; Scheduling Performance; Structural Empowerment; Structural Equation Modeling
Azari-N, Rahman; Kim, Yong-woo. (2012). Comparative Assessment of Life Cycle Impacts of Curtain Wall Mullions. Building And Environment, 48(1), 135 – 145.
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Abstract
Glass curtain wall (Cw) systems have been inevitable elements of commercial buildings for over a century. The systems mainly consist of mullion materials and glazing units that are selected and designed to achieve the desired structural, thermal and daylighting performances as well as to meet cost and aesthetic concerns. The health and environmental life cycle impacts of CW systems, however, are not usually considered in design. The main objective of this paper is to study how change of mullion materials would affect the health and environmental impacts associated with a typical CW system over its life cycle. The mullion materials studied for the purpose of this paper include extruded aluminum, carbon steel and glulam timber. Also, the health and environmental impact categories of interest include global warming, acidification, eutrophication and human toxicity. To achieve the objective, a process-based cradle-to-gate attributional Life Cycle Assessment (LCA) method was applied. Results indicate that CW system with glulam timber mullions causes the least and CW system with extruded aluminum mullions causes the most damage to the environment and human health over their life cycle. A CW system with carbon steel mullions falls in-between. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords
Commercial Building; Comparative Assessment; Curtain Walls; Environmental Life Cycle; Glass Curtain Walls; Inventory Analysis; Life Cycle Assessment (lca); Life Cycle Impacts; Aluminum Coated Steel; Ecodesign; Eutrophication; Global Warming; Health; Life Cycle; Office Buildings; Timber; Walls (structural Partitions); Energy; Wood; Products; Life Cycle Assessment; Environmental Impact; Curtain Wall; Mullion Material; Acidification; Aluminum; Attributional Life Cycle Assessment; Buildings; Carbon; Environmental Health; Glass; Glulam; Human Health; Humans; Materials Life Cycle; Steel; Toxicity
Kim, Taehoon; Kim, Yong-Woo; Cho, Hunhee. (2021). A Simulation-Based Dynamic Scheduling Model for Curtain Wall Production Considering Construction Planning Reliability. Journal Of Cleaner Production, 286.
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Abstract
Appropriate production scheduling of curtain wall systems is essential for the successful completion of construction projects. The construction process of the curtain wall system is mainly on the critical path and accounts for 10-15% of the total construction cost. Should curtain wall products not be timeously delivered to the construction site, construction projects are likely to fall behind schedule with most relevant activities on curtainwall installation on a critical path. However, due-date uncertainty caused by a contractor's lack of planning reliability causes the curtain wall production schedule to become complex and changes the due date after the initial order. In this regard, this study proposes a discrete event simulation-based dynamic scheduling model for curtain wall production to deliver products on time to the construction site by considering each construction project's planning reliability. Through simulation experiments, the validity and effectiveness of the proposed model were tested. The results of this study will help the successful completion of construction projects by ensuring the progress of the curtain wall system construction and follow-up activities following the construction schedule. (C) 2020 Elsevier Ltd. All rights reserved.
Keywords
Construction Industry; Discrete Event Simulation; Dynamic Scheduling; Production Control; Production Planning; Project Management; Reliability; Scheduling; Walls; Construction Planning Reliability; Construction Schedule; Curtain Wall System Construction; Construction Project; Discrete Event Simulation-based Dynamic Scheduling Model; Curtain Wall Production Schedule; Curtain Wall Installation; Curtain Wall Products; Total Construction Cost; Critical Path; Production Scheduling; Off-site Construction; Demand Variability; Job Shops; Precast; Minimize; Number; Curtain Wall; Simulation; Planning Reliability; Dispatching Rule
Yi, June-Seong; Kim, Yong-Woo; Kim, Ki-Aeng; Koo, Bonsang. (2012). A Suggested Color Scheme for Reducing Perception-Related Accidents on Construction Work Sites. Accident Analysis And Prevention, 48, 185 – 192.
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Abstract
Changes in workforce demographics have led to the need for more sophisticated approaches to addressing the safety requirements of the construction industry. Despite extensive research in other industry domains, the construction industry has been passive in exploring the impact of a color scheme: perception-related accidents have been effectively diminished by its implementation. The research demonstrated that the use of appropriate color schemes could improve the actions and psychology of workers on site, thereby increasing their perceptions of potentially dangerous situations. As a preliminary study, the objects selected by rigorous analysis on accident reports were workwear, safety net, gondola, scaffolding, and safety passage. The colors modified on site for temporary facilities were adopted from existing theoretical and empirical research that suggests the use of certain colors and their combinations to improve visibility and conspicuity while minimizing work fatigue. The color schemes were also tested and confirmed through two workshops with workers and managers currently involved in actual projects. The impacts of color schemes suggested in this paper are summarized as follows. First, the color schemes improve the conspicuity of facilities with other on site components, enabling workers to quickly discern and orient themselves in their work environment. Secondly, the color schemes have been selected to minimize the visual work fatigue and monotony that can potentially increase accidents. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords
Construction Industry Accidents; Industrial Hygiene; Industrial Safety; Empirical Research; Sensory Perception; Work Environment; Demographic Surveys; Job Performance; Color Scheme; Construction Industry; Labor Demography; Perception-related Accident; Accident Prevention; Accidents; Demography; Human Resource Management; Population Statistics; Color Schemes; Construction Works; Dangerous Situations; Rigorous Analysis; Safety Requirements; Temporary Facilities; Work Environments; Psychological Climate; Drivers; Emotion; Model
Soltaninejad, Mostafa; Fardhosseini, Mohammad Sadra; Kim, Yong Woo. (2021). Safety Climate and Productivity Improvement of Construction Workplaces Through the 6S System: Mixed-Method Analysis of 5S and Safety Integration. International Journal Of Occupational Safety & Ergonomics, 28(3), 1811-1821.
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Abstract
The purpose of this study is to develop a framework for integrating essential safety practices (visualization, job safety analysis and plan-do-check-act) into 5S steps and validate it. First, 18 interviews with a snowball sample of construction workers, safety representatives, supervisors and site and project managers were conducted. A grounded theory method was utilized to code the interview data. The results revealed that the studied construction companies implement a systematic safety-based methodology to minimize construction work injuries. Second, to validate the proposed framework, a pre-test and post-test study was applied. The case and control groups (26 participants) answered a 6S questionnaire before the 6S system and 1 month after implementation. The results revealed that safety climate and productivity significantly increased for the case group but reduced for the control group during time.
Keywords
5s Method; 6s System; Grounded Theory; Lean Construction; Productivity; Safety Climate; Health; Management; Leadership; Culture; Impact
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
Shim, Yukyung; Jeong, Jaemin; Jeong, Jaewook; Lee, Jaehyun; Kim, Yongwoo. (2022). Comparative Analysis of the National Fatality Rate in Construction Industry Using Time-series Approach and Equivalent Evaluation Conditions. International Journal Of Environmental Research And Public Health, 19(4).
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Abstract
Fatality rates such as fatalities per full-time equivalent workers are officially used to compare the risk level of the construction industry among various countries. However, each country evaluates the fatality rate using different conditions. This paper presents the comparison of fatality rates of various countries using conventional (national data) and pair (equivalent condition) methods through a time-series approach. The research was conducted in three stages. The risk level was evaluated in order in South Korea (1.54), Japan (0.84), Mexico (0.83), China (0.70), United Kingdom (0.15), and Singapore (0.13) in terms of national data. However, the risk level was re-evaluated in order in China (2.27), South Korea (2.05), Mexico (1.23), Singapore (0.98), Japan (0.80), and United Kingdom (0.47) in terms of equivalent conditions. The risk level of each can be changed when the fatality rate is compared under given equivalent conditions.
Keywords
Fatality Rate; Risk Level; Full-time Equivalent Workers; Equivalent Evaluation Conditions; Time-series Analysis; Occupational Accidents; United-states; Injuries; Korea; Work; Comparative Analysis; Equivalence; Manual Workers; Risk Levels; Construction Industry; Fatalities; Risk Assessment; Safety Management; Industrial Accidents; Environmental Protection; Time Series; Accident Investigations; United Kingdom--uk; South Korea; Mexico; United States--us; Singapore; China; Japan