• Nuclear Engineering and Technology
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• v.47 no.3
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• pp.362-379
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• 2015

In this study, Nuclear Power Plant (NPP) construction schedule delay risk assessment methodology is developed and the construction delay risk is assessed for turnkey international NPP projects. Three levels of delay factors were selected through literature review and discussions with nuclear industry experts. A questionnaire survey was conducted on the basis of an analytic hierarchy process (AHP) and Relative Importance Index (RII) methods and the schedule delay risk is assessed qualitatively and quantitatively by severity and frequency of occurrence of delay factors. This study assigns four main delay factors to the first level: main contractor, utility, regulatory authority, and financial and country factor. The second and the third levels are designed with 12 sub-factors and 32 sub-sub-factors, respectively. This study finds the top five most important sub-sub-factors, which are as follows: policy changes, political instability and public intervention; uncompromising regulatory criteria and licensing documents conflicting with existing regulations; robust design document review procedures; redesign due to errors in design and design changes; and worldwide shortage of qualified and experienced nuclear specific equipment manufacturers. The proposed combined AHP-RII methodology is capable of assessing delay risk effectively and efficiently. Decision makers can apply risk informed decision making to avoid unexpected construction delays of NPPs.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.520-529
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• 2007

Apportioning responsibilities of concurrent delay to the owner and the contractor is a difficult task, due to the sophisticate nature both in the schedule and in the factors that cause the delay. This research attempts to develop a simplified yet systematic approach that can be used for a fair apportionment of concurrent delay. A concurrent delay is defined herein as when the contractor and the owner have both caused independent critical path delays during the same approximate time period. Incorporating the concepts of windows analysis and critical path method (CPM), the developed approach has three "windowing of delay" steps to quickly apportion the delay in each of these windows, and a fourth step to sum up those apportioned delays to obtain each party's final responsibilities. This developed approach is found to be simple and effective at this stage; it will be tested against real cases in the near future.

• Journal of the Korea Institute of Building Construction
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• v.18 no.4
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• pp.385-394
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• 2018

There have been frequent reports of schedule delays due to various risks of remodeling projects, which are different from new construction. Therefore, this study was carried out to analyze the risk factors inherent in the remodeling project and the likelihood of schedule delay occurrence in the remodeling construction work. To analyze the relationship between the risk factors and the likelihood of schedule delays of remodeling projects, (1) a prototype of the office building remodeling work was developed through the analysis of existing case and literature, (2) a questionnaire survey was conducted on 29 construction managers who have been or are currently conducting remodeling projects, and (3) after evaluating the reliability of the collected questionnaire results, the relationship between the two elements, which denotes (i) likelihood of schedule delays per each work, (ii) importance of risk factors, and (iii) risk factors affecting schedule delay in remodeling work, was suggested. Using the results of this study, it is expected to develop a plan for preventing the schedule delay of the office building remodeling work through control the risk factors that may cause schedule delays.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.1 no.1
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• pp.77-97
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• 1994

The circadian system represents a temporal order which is mediated by the mutual coupling of oscillators and by the synchronizing effects of zeitgebers. It is known that well-being of man depends partly on the maintenance of this order, and that repeated or long lasting disturbances to it such as shift work will Cause harmful effects. This study was a quasi-experimental study to test the effect of shift directions for the clinical nurses on the circadian rhythm. Fourteen nurses working at the general units of Y hospital were selected according to the established criteria. Fourteen subjects were assigned to a weekly shift but the directions of shift work were phase delay first and then phase advance or vice versa. Oral temperature, total sleeping time, frequency of sleep-wake cycle, fatigue, mental performance, and physical symptom were measured during these days except holidays. The data collection period was from April 26, 1993 to July 3, 1993. MANOVA and Wilcoxon signed rank test were used for statistical analysis. The results are summarized as follows. 1. Having worked on evening and night shifts in either phase delay or phase advance schedules, temperature rhythms of shift workers were gradually adapted to the new sleep-wake cycles. A complete adaptation to work on the night shift was achieved the sixth day of the night shift in the phase delay schedule compared to the partial adaptation to the work on the night shift in the phase advance schedule. Accordingly, by putting evening shift between day and night shifts, it will be possible for circadian rhythm to adapt easily to the night shift. 2. There were differences in the total sleeping time, frequency of steep-wake cycle, fatigue, and physical symptom except for mental performance between night shift and day, evening shift. This indicates further that shift workers working on the night shift have a hard time adapting to the shift work compared to the other shifts. 3. Evaluating all the acrophases of temperature rhythm either in phase delay or phase ad-vance schedules, it was shown that night to evening shift in the phase ad-vance schedule revealed the smallest phase move. Also phase advance schedule showed poorer adaptation to shift work than phase delay schedule in connection with total sleeping time, frequency of sleep-wake cycle, fatigue, mental performance, and physical symptom. It is suggested, taken together, these findings reflect that phase delay schedule facilitated the degree of adjustment to the shift work compared to the phase advance schedule.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.109-117
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• 2023

Schedule delays present a major risk factor, as they can adversely affect construction projects, such as through increasing construction costs, claims from a client, and/or a decrease in construction quality due to trims to stages to catch up on lost time. Risk management has been conducted according to the importance and priority of schedule delay risk, but quantification of risk on the depth of schedule delay tends to be inadequate due to limitations in data collection. Therefore, this research used the BERT (Bidirectional Encoder Representations from Transformers) language model to convert the contents of aconstruction log, which comprised unstructured data, into WBS (Work Breakdown Structure)-based structured data, and to form a model of classification and quantification of risk. A process was applied to eight highway construction sites, and 75 cases of rain schedule delay risk were obtained from 8 out of 39 detailed work kinds. Through a K-S test, a significant probability distribution was derived for fourkinds of work, and the risk impact was compared. The process presented in this study can be used to derive various schedule delay risks in construction projects and to quantify their depth.

• Korean Journal of Construction Engineering and Management
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• v.6 no.3 s.25
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• pp.81-89
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• 2005

Delay schedule coming about duration extension is happening essentially because public construction project consist of many sub contractor. The method which can calculate delay day is suggested by many studies in case of happing delay schedule, but It is difficult to apply to real construction project because there is no mention about the control of The law of contract according to delay schedule. The law of Contract which is cost of account has more uncertain problem than FIDIC condition of contract. This study suggests method which can make extension of duration procedure clear in case of happing the reason of design change related with activity duration during carrying on construction, and a submission process of the reason of duration extension and modify schedule making way about section which is basis of calculating contract amount clear.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.179-185
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• 2007

In large station with high density traffic, trains can be hardly controlled by CTC but by station dispatcher because CTC has difficulties in monitoring all states of affairs happening within each station such as departures, arrivals of many trains from different lines and shunting of trains to move between yards and platforms, etc. Therefore the station's dispatcher has to make quick decision about how to reschedule the times and routes for all the trains scheduled within a specific time window. And such decision becomes harder when an unexpected delay occurs because a delay occurring in a train propagates other trains as time goes on. Generally, it is called the conflict detection and resolution to adjust beforehand the distorted schedule due to a delay to original schedule. Our research is different from the state of the arts in that ours determines simultaneously the routes and the times of arrival and departure of trains, although others do only the arrival and departure time of the trains without considering the alternative routes and shunting of the station. This study suggests a mathematical approach for how to detect in advance and resolve efficiently the conflicts occurring within a station and it will be shown how to reduce delay using our approach by means of analysing the schedule of ChyungRyangRi station.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.637-642
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• 2007

The sum of each work duration are entire period in construction project. Each work occurs to be late, the total period of construction project will delays. Therefore, the total period of construction project will not be delayed if probability of working progress makes higher. Finding each work's constraints performs constraints analysis in process of construction for checking probability of working progress. Grasp work's constraints through the constraints analysis and removes. This research will show preventing delay of consruction project, through constraints analysis process.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.616-623
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• 2022

Some regions and states, such as Wyoming, have harsh weather conditions, forcing most transportation projects to be completed under tight schedules. However, construction projects are not only delayed by weather conditions, but also delayed by other factors such as contractor's competency, resource availability, coordination issues, and safety. Also, the construction method, geographical location of the projects, and inability to follow baseline schedules accurately due to the contractor's resource allocation are also reasons for the delay. This paper discusses the main reasons for the delay in the public transportation projects based on Daily Work Reports (DWRs) from five different transportation projects of the last three years in Wyoming. This paper focuses on the inconsistencies of the contractor's schedules to complete the project according to the baseline schedule. First, the authors collected DWRs and baseline schedules from the Wyoming Department of Transportation (WYDOT). Second, the DWR data are compared against the baseline schedules to determine the reasons for delaying their significance. Finally, the paper presents the recommendations to mitigate the effects of delays on public transportation projects as well as to improve the documentation process of DWR data.

• Knowledge Management Research
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• v.22 no.1
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• pp.1-19
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• 2021

Large-scaled hospital information system projects are often delayed than originally planned. Regarding project management, it is necessary to examine main factors triggering the schedule delay and to analyze the causality of such delay. This study tries to find the delay factors and causal relationship between them based on the case of the hospital information system development project by using the grounded theory method. It turned out that 'unrealistic scheduling' affects overall schedule delays like domino phenomenon, and 'poor analysis of existing systems' leads to poor quality of work analysis while 'poor subsystem integrated interface' triggers poor design quality. This study found out the factors affecting the delay of a project, analyzing cause-and-effect relationships between them in the academic side. From the practical view, it shows a solution to minimize delays in the project schedule for each of SI companies, hospitals and project managers.