• Nuclear Engineering and Technology
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• 제47권3호
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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.

• 시스템엔지니어링학술지
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• 제11권1호
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• pp.9-24
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• 2015

Construction industry faces a lot of inherent uncertainties and issues and the construction phase of nuclear power project is not free from this risk. This paper investigates promising methodologies to be used on nuclear power plant (NPP) construction schedule delay risk assessment by using entry level systems engineering approach. This study contains how the initial concept for the risk assessment methodology has been developed. In this point of view, this work structured on three main phases: needs analysis (NA), concept exploration (CE), and concept definition (CD) through systems engineering (SE) approach. Traditionally, the SE process is applied to technical development programs but this study opens up a new avenue that SE can also be successfully applied to the development and optimization of the risk assessment model. This study provides a rational and systematic process for developing and selecting the best risk assessment model. This paper selects analytic hierarchy process (AHP) method to assess NPP construction schedule delay risk for international project. As conclusion, the proposed concept and selected method can discriminate successfully and clearly among schedule delay risk assessment methods.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2003년도 학술대회지
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• pp.217-221
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• 2003

본 연구에서는 공동주택공사에서 발생하는 공기지연 리스크에 대한 분류체계와 분석방법을 제안하였다. 서울${\cdot}$경기 지역과 부산${\cdot}$경남 지역의 공동주택공사 현장을 중심으로 실무자 면담 및 설문조사를 실시하였고, 그 결과를 바탕으로 주요 광종 분류와 각 공종의 공기지연 리스크 수준과 지수를 산정하였다. 본 연구는 공동주택공사의 주요 공종인 토공사, 골조공사, 조적${\cdot}$미장공사, 창호${\cdot}$유리공사, 수장공사의 공기지연 리스크 요인의 리스크 수준, 지수 그리고 순위를 분석하여 공기지연 리스크 관리 시스템 구축을 위한 기초적인 자료를 제시하는 것을 목적으로 하였다.

• 한국의류학회지
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• 제33권11호
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• pp.1707-1718
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• 2009

This study examines the effects of perceived risks on purchase decision behavior among Internet fashion consumers. The study survey used a self-administered questionnaire and a total data of 244 responses were used for analysis. The results of this study are as follows: First, the perceived risks consist of 6 factors, quality risk, counterfeit product risk, credit dealing risk, social/psychological risk, size and appearance risk, and delivery risk. The purchase decision behavior consist of 3 factors, delay of purchase decision, website switching, and offline conversion behavior. Second, purchase time positively affected the quality risk and credit dealing risk. Purchase frequency negatively affected the quality risk and credit dealing risk. Third, the quality risk, size and appearance risk, counterfeit product risk, and credit dealing risk positively affected the delay of purchase decisions. Quality risk and counterfeit product risk positively affected website switching. In addition, quality risk, social/psychological risk, and credit dealing risk positively affected the offline conversion behavior. Fourth, credit dealing risk negatively affected a short term purchase intention and the delivery risk negatively affected a long term purchase intention. The social/psychological risk and credit dealing risk negatively affected the repurchase intention.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.599-599
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• 2015

This research attempts to resolve the construction delay issues of indirect delays by developing the "Delay Responsibility Determination Model" (DRM) based on probabilistic risk analysis. DRM is envisioned to provide a way of quantitatively analyzing impacts of delayed activities while considering both direct and indirect influences. With the successful development of DRM, it would be possible to present relative probabilistic measures to all the related stakeholders in terms of their contributions to schedule delays. Upon the development completion of DRM, "Korean Construction Delay Claim/Dispute Resolution Protocols" will also be prepared to facilitate the effective use of DRM.

• 한국안전학회지
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• 제33권3호
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• pp.83-91
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• 2018

This paper suggests a weibull time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). Assuming three types of loss functions for delayed time in failure cause detection, the risk of each failure cause is evaluated as its occurring frequency and expected loss. Since the closed form solution of the risk metric cannot be obtained, a statistical computer software R program is used for numerical calculation. When the occurrence and detection times have a common shape parameter, though, some simple results of mathematical derivation are also available. As an enormous quantity of field data becomes available under recent progress of data acquisition system, the proposed risk metric will provide a more practical and reasonable tool for evaluating the risks of failure causes in FMEA.

• 한국안전학회지
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• 제29권1호
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• pp.1-6
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• 2014

With increasing number of citizen using subway stations everyday, safety, health and comfort of passengers and occupants became an important social issue. Considering the fact that various physical variables and pollutants are related to indoor air quality (IAQ) which may cause health problem, IAQ need to be closely monitored and controlled in multiple locations in subway stations. This study is a continuation of the previous studies and delay induced in wireless-wired network is experimentally evaluated and the risk involved is assessed. In doing that, a key parameter is identified to be the network delay in different network media. Application of information-theoretic measure to assess the risk in network delay is then discussed. The idea is based on the general principles of engineering design and their applications to quantification of uncertainty in network delay. Experimental results show that more risk is involved in wireless data communication. Efficient and fast conversion of transmission data in both LonWorks/IP server and ZL converter is also noted.

• 한국건축시공학회지
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• 제19권5호
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• pp.467-475
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• 2019

Delay is one of the most critical issues for construction projects and leads to huge losses in both developing and industrialized countries. The construction sector in Rwanda, a rapidly-developing nation, is no exception. Delays can be mitigated only once we have identify their primary causes, and these may not be the same in each region. This study aims to ascertain the main critical factors responsible for delays in building construction in Rwanda through an intensive literature review and questionnaire survey. A total of 40 delay causative factors were obtained from a literature review and were further classified into nine major categories. The questionnaire survey was distributed to about 80 respondents from clients, contractors, and consultants. From the list of 40 different factors, the top twelve most critical causes were identified as stoppage of work due to cash flow constraints, delay in approving design documents, confidentiality of physical plan, price fluctuations and delay in approving significant change, change orders, delay in performing inspections, Ineffective project planning, inadequate drawing details, unqualified labor, lack of materials on the market and dishonesty.

• 한국건설관리학회논문집
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• 제19권5호
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• pp.22-31
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• 2018

리모델링 사업의 고유 리스크 요인들로 인해, 리모델링 사업의 실패가 빈번하게 발생하고 있는 실정이며 특히 공기지연이 거의 대부분의 리모델링 프로젝트에서 발생하고 있는 실정이다. 이러한 리모델링 프로젝트의 공기지연을 야기하는 리스크요인들이 모든 리모델링 프로젝트에 공통적으로 발생하는 것은 아니며, 해당 프로젝트의 다양한 특성에 따라 리스크 요인들의 발생가능성이 영향을 받게 된다. 이러한 맥락에서, 리모델링 프로젝트를 수행한 경험이 있는 29명의 현장관리자들을 대상으로 수행된 신뢰성 있는 설문조사 결과를 바탕으로, (1) 리모델링 프로젝트의 속성들이 리스크 요인의 발생에 얼마나 빈번하게 영향을 미치는지를 평가한 "프로젝트의 속성별 중요도"를 산정하였고, (2) 어떤 리스크 요인의 발생가능성이 가장 큰지를 평가한 "리모델링 사업의 공기지연 리스크 요인별 중요도" 그리고 (3) 이상의 두 가지를 혼합한, "각각의 리스크 요인의 발생에 영향을 미치는 프로젝트 속성별 영향도"를 분석하였다. 본 연구를 통하여, 리모델링을 고려하는 건축물의 다양한 특성들과 공기지연 리스크 발생가능성 사이의 관계를 다각적인 측면으로 분석하였고, 이를 통해, 리모델링을 계획하고 있는 발주자가 해당 프로젝트의 오피스의 특성에 따라 발생가능성이 높은 공기지연 리스크를 사전에 파악할 수 있을 것으로 기대된다.

• 품질경영학회지
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• 제44권2호
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• pp.373-388
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• 2016

Purpose: This paper suggests a hierarchical time delay model to evaluate failure risks in FMEA(failure modes and effects analysis). In place of the conventional RPN(risk priority number), a more reasonable and objective risk metric is proposed under hierarchical failure cause structure considering time delay between a failure mode and its causes. Methods: The structure of failure modes and their corresponding causes are analyzed together with the time gaps between occurrences of causes and failures. Assuming the severity of a failure depends on the length of the delayed time for corrective action, a severity model is developed. Using the expected severity, a risk priority metric is defined. Results: For linear and quadratic types of severity, nice forms of expected severity are derived and a meaningful metric for risk evaluation is defined. Conclusion: The suggested REM(risk evaluation metric) provides a more reasonable and objective risk measure than the conventional RPN for FMEA.