• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.107-119
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• 2021

Recently, interest in remodeling apartment houses has been increasing due to problems such as a lack of parking spaces for old apartment houses. However, no method was suggested to predict the construction period of the apartment remodeling project. Unlike general apartment new construction, apartment remodeling construction involves demolition or reinforcement work, so a realistic remodeling construction period calculation plan differentiated from the existing construction period should be proposed. Therefore, this study intends to present a model for deriving the construction period of the underground parking lot of the apartment remodeling construction. Each construction period was calculated based on 19 activities of underground parking lot remodeling work through review of previous studies and expert advice. Activity's workload data and productivity data were derived to calculate the construction period, and the number of inputs and equipment inputs by Activity were determined to correct the productivity data. The construction period of Activity was calculated using the derived data, and the criteria for calculating the overlapping period for each Activity were presented to enable realistic construction period and scheduled schedule. As a result of predicting the accuracy of the construction period through the verification of the case complex, it is expected that it will be possible to predict the approximate construction period of the underground parking lot of the apartment remodeling construction in the future.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.416-421
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• 2001

The domestic reinforcement concrete works have mainly worked the process of re-bar fabrication/assembly on site and re-bar works affected by structural safety, durability, and schedule with form work. Accordingly, This study analyzes the process of re-bar fabrication/assembly on site to apply lean production principles to construction Value Stream Analysis(VSA) is analyzed into value-adding activity and non-value-adding activity on construction process through value analysis and Value Stream Mapping(VSM). In the results, non-value-adding activity generates waste such as the activity steps, labors, equipments, materials, time, and so on. Additionally, push-driven production is investigated making low productivity from the overproduction and so on. To resolve the problems in the process, The purpose of this paper eliminates waste factor through maximizing the value-adding activity generating value added and minimizing non-value adding activity. Particularly, it makes flow production and pull-driven production through minimizing work-in-process(WIP ).

• International conference on construction engineering and project management
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• 2015.10a
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• pp.101-103
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• 2015

Scientific methods that measure the physical demand requirements of a construction operation have not been arrived at maturity in construction community. It is attributed to the difficulty involved in performing controlled experiments on the operation and its' volatile jobsite environment. This paper presents a method that measures the physical demand requirement of the waterproofing activity and verifies the differences between various operations (e.g., a primer painting and a polyurethane coating) consisting of the activity. Two hypotheses, which are involved in the operations, are summarized as follows: [Hypothesis 1] when one performs the same amount of work; the one's average heart rate required for the polyurethane coating operation is higher than that required for the primer painting operation. [Hypothesis 2] when one performs the same amount of work, the one's break time required for the polyurethane coating operation is longer than that required for the primer painting operation.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.109-110
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• 2015

This paper presents a computational method that identifies an exact set of optimal overlap rates between critical activities to meet job site specific needs by using rework cost-slope. The procedures to compute the exact solution are provided in peudocode algorithm. The method is coded into Exact Concurrent Construction Scheduling system that allows practitioners to make more informed decision in accordance with the site-specific condition involved in the overlapping of critical activities. Test cases verify the validity of the computational method and the usability of the system.

• Journal of the Korean Professional Engineers Association
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• v.24 no.5
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• pp.129-137
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• 1991

In case a firm proceeds with TQC the activity of QCC, one of the activities concerned with TQC, is made first of all. There fore, in consideration that TQC could not be successful with the activity of QCC being unsuccessful a firm underlines activating QCC and makes considerable support of the educational discipline. However, as for the data of TQC having been introduced in domestic country no data related to construction industry have been found, all of them being concerned with manufacturing industry and it has happened that some firms of the construction industry make the negative reaction to the activity of QCC. So some of firms including our one have prepared and published their own texts and made them available by utilizing the translated Japanese data which were attained through Japanese construction firms. It is thought that a problem has been caused by the above-stated. While Japanese firms have made R & D of the features concerning to the most basic QCC activity for themselves, Korean ones have just followed and taken advantage of those originated by Japanese without being conscious of the basic idea, and this has caused the consequent failing of QCC activity. In other word, the emphasis of the results only rather than process has brought about the unsuccessful QCC activity.

• Korean Journal of Construction Engineering and Management
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• v.4 no.4 s.16
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• pp.69-79
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• 2003

About 93$\%$ of domestic teal estate construction firms registered as the end of 2001 recorded net profits of only less than 500 million won(including firms in the red) for the term. As a result of having analyzed the ratios of sales costs and the structural ratios of sales costs for the past 10 years, it was found that there have been great changes in structural ratios of sales costs. Material costs and labor costs have gradually decreased, but outsourcing costs of processing have greatly increased. In order to find activity points which are fundamental to cost control, the methods of new activity based cost management have been pursued. The characteristics of real estate construction industry lie in the fact that contract prices (sales in) are fixed and amounts of profits differ depending on the use of costs. In order to create maximum profits from fixed contract prices, the new activity based cost management has been proposed. The control of operation budgets and management costs is designed to control their schedules and expenses in different respects. Operation budgets ate executed with specific activities and management costs are controlled as a form of material costs, labor costs, out sourcing costs and expenses which are details of expenditure. In order to execute them by using the methods of new activity based cost management, first of all, we have to analyze what activity drivers ale and how much added values such activities can create. It is considered as a method of cost management which is necessary far the survival management of real estate construction industry.

• Architectural research
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• v.4 no.1
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• pp.53-61
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• 2002

The typical Critical Path Method (CPM) leaves it to the construction managers to overcome two problems in developing networks. First, the construction manager needs to prepare information on the type of activities and their precedence relations in order to develop a network schedule. Second, he or she can include space information into the network schedule such as the locations where the activities take place, only with difficulty. These two problems make it difficult for an inexperienced person to create a network. The purpose of this paper is to provide construction managers with set equations of creating a network schedule for multiunit projects. A space-resource combined network creation are presented in this paper, which includes equations for generating a list of required activities, their precedence relations, and information on their location. Information on the space (location) and the resource is the required data for this method. Based on this information, this method divides a project into a number of activities so that each activity contains the information on the location where the activity takes place and the principal resource required for that activity. Precedence relations are then obtained from the sequence of space and resource. This method has the potential to reduce human efforts in scheduling activities.

• Journal of Construction Engineering and Project Management
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• v.3 no.2
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• pp.21-34
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• 2013

Various risk factors affect construction projects. Due to the uncertainties created by risk factors, actual activity durations frequently deviate from the estimated durations in either favorable or adverse direction. For this reason, evaluation of schedule uncertainty is required to make decisions accurately when managing construction projects. In this regard, this paper presents a new computer simulation model - the Repetitive Schedule Risk Analysis Model (RSRAM) - to evaluate unit-based repetitive building project schedules under uncertainty when activity durations and risk factors are correlated. The proposed model utilizes Monte Carlo Simulation and a Critical Path Method based repetitive scheduling procedure. This new procedure concurrently provides the utilization of resources without interruption and the maintenance of network logic through successive units. Furthermore, it enables assigning variable production rates to the activities from one unit to another and any kind of relationship type with or without lag time. Details of the model are described and an example application is presented. The findings show that the model produces realistic results regarding the extent of uncertainty inherent in the schedule.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.350-353
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• 2006

Generally, 4D CAD can be used for visualizing construction schedule information in railway construction project. It is important that 3D CAD object should be represented by real construction situation according to construction site condition. However, it is difficult to visualize real construction situation in 4D CAD viewer because 3D objects should be separated by limited duration of each activity. This study suggests a morphing technology for visualizing 4D object by each activity schedule according to real construction progress.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.359-366
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• 2013

Although many research efforts have been conducted to address the effect of crew members' work skills (e.g., technical and planning skills) on work performance (e.g., work duration and quality) in construction projects, the relationship between skill and performance has generated a great deal of controversy in the field of management (Inkpen and Crossan 1995). This controversy can lead to under- or over-estimations of the overall project schedule, and can make it difficult for project managers to implement appropriate managerial policies for enhancing project performance. To address this issue, the following aspects need to be considered: (a) work performances are determined not only by individual-level work skill but also by the group-level work skill affected by work team members, each member's role, and any working behavior pattern; (b) work planning has significant effects on to what extent work skill enhances performance; and (c) different types of activities in construction require different types of work, skill, and team composition. This research, therefore, develops a system dynamics (SD) model to analyze the effects of both individual-and group-level (i.e., multi-level) skill on performances by utilizing the advantages of SD in capturing a feedback process and state changes, especially in human factors (e.g., attitude, ability, and behavior). The model incorporates: (a) a multi-level skill evolution and relevant behavior development mechanism within a work group; (b) the interaction among work planning, a crew's skill-learning, skill manifestation, and performances; and (c) the different work characteristics of each activity. This model can be utilized to implement appropriate work planning (e.g., work scope and work schedule) and crew management policies (e.g., work team composition and decision of each worker's role) with an awareness of crew's skill and work performance. Understanding the different characteristics of each activity can also support project managers in applying strategic work planning and crew management for a corresponding activity, which may enhance each activity's performance, as well as the overall project performance.