Risk analysis model for regional railroad investment

2017 ◽  
Vol 34 (1) ◽  
pp. 164-173 ◽  
Author(s):  
Sunduck Suh ◽  
Wonho Suh ◽  
Jung In Kim
Keyword(s):  
Risk Analysis ◽  
Financial Analysis ◽  
Mathematical Optimization ◽  
Optimal Solution ◽  
Optimization Procedure ◽  
Solution Procedure ◽  
Risk Modeling ◽  
Analysis Model ◽  
Content Type ◽  
Goals And Objectives

Purpose The purpose of this study is to model risks in financial analysis. These risks associated with uncertainties in the projects should be properly addressed to ensure proper decision regarding the projects. Performance indicators should be developed and assessing risks has high priority. All these activities comprise appraisal, and based on these, a proper course of action should be recommended. Design/methodology/approach To analyze the attractiveness of a project for foreign regional railroad investment or participation, the project should be analyzed in a systematic way. First, the project’s goals and objectives should be evaluated for compatibility. Also, criteria of acceptability for stakeholders should be checked against output from the project. Usually, a project can have many alternatives, and impacts of each alternative should be analyzed in terms of quantitative and qualitative forecasts of impacts. Benefits and costs need to be counted in proper units of measurement per goals and objectives. Findings This paper shows that risk modeling can reflect uncertainty in decision-making and provide robustness of modeling process and improved communication. Also, challenges are presented in using risk analysis. Originality/value To overcome the shortcomings of traditional mathematical optimization model in identifying best sets of projects for private application, the proposed model finds ways to incorporate risk management components for the optimization procedure. Based on simulation results, a brute force solution procedure using enumeration can be used. Another approach is recommended to use the genetic algorithm process to reduce the number of alternatives to search to reach an optimal solution.

Scenario based evaluation of a cost risk model through sensitivity analysis

2015 ◽  
Vol 22 (4) ◽  
pp. 403-423 ◽  
Author(s):  
Önder Ökmen ◽  
Ahmet Öztaş
Keyword(s):  
Risk Factors ◽  
Risk Analysis ◽  
Risk Model ◽  
Practical Method ◽  
Cost Evaluation ◽  
Sensitivity Analyses ◽  
Analysis Model ◽  
Content Type ◽  
Detailed Evaluation ◽  
Cost Risk

Purpose – Actual costs frequently deviate from the estimated costs in either favorable or adverse direction in construction projects. Conventional cost evaluation methods do not take the uncertainty and correlation effects into account. In this regard, a simulation-based cost risk analysis model, the Correlated Cost Risk Analysis Model, previously has been proposed to evaluate the uncertainty effect on construction costs in case of correlated costs and correlated risk-factors. The purpose of this paper is to introduce the detailed evaluation of the Cost Risk Analysis Model through scenario and sensitivity analyses. Design/methodology/approach – The evaluation process consists of three scenarios with three sensitivity analyses in each and 28 simulations in total. During applications, the model’s important parameter called the mean proportion coefficient is modified and the user-dependent variables like the risk-factor influence degrees are changed to observe the response of the model to these modifications and to examine the indirect, two-sided and qualitative correlation capturing algorithm of the model. Monte Carlo Simulation is also applied on the same data to compare the results. Findings – The findings have shown that the Correlated Cost Risk Analysis Model is capable of capturing the correlation between the costs and between the risk-factors, and operates in accordance with the theoretical expectancies. Originality/value – Correlated Cost Risk Analysis Model can be preferred as a reliable and practical method by the professionals of the construction sector thanks to its detailed evaluation introduced in this paper.

Instances for the problem of pre-positioning emergency supplies

2019 ◽  
Vol 9 (2) ◽  
pp. 172-195 ◽  
Author(s):  
Renata Turkeš ◽  
Kenneth Sörensen
Keyword(s):  
Case Studies ◽  
Disaster Preparedness ◽  
Single Case ◽  
Statistical Significance ◽  
Public Library ◽  
Solution Procedure ◽  
Analysis Model ◽  
Content Type ◽  
Managerial Implications ◽  
Problem Instances

Purpose Despite a growing body of research on the problem of increasing disaster preparedness by pre-positioning relief supplies at strategic locations, there is a lack of a benchmark set of problem instances that hinders thorough hypotheses testing, sensitivity analysis, model validation or solution procedure evaluation. The purpose of this paper is to address this issue by constructing a public library of diverse pre-positioning problem instances. Design/methodology/approach By carefully manipulating some of the instance parameters, the authors generated 30 case studies that were inspired by four instances collected from the literature that focus on disasters of different type and scale that occurred in different parts of the world. In addition, the authors developed a tool to algorithmically generate arbitrarily many diverse random instances of any size. Findings For many purposes, the problem library can eliminate or reduce the time-consuming process of data collection, conversion, digitization, calibration and validation, while simultaneously increasing the statistical significance of research results and allowing comparison with different works in the literature. Research limitations/implications The case studies are inspired by only four disasters, and some of the instance parameters are defined in a reasonable, albeit arbitrary way. The instances are also limited by the underlying problem assumptions. Practical implications The instances provide a more comprehensive and balanced experimental setting (compared to a single case study) that can be used to study the pre-positioning and related problems, or derive managerial implications that can directly benefit the practitioners. Social implications The instances can be used to derive practical guidelines that humanitarian workers can use on the ground to better plan their pre-positioning strategies and therefore minimize human suffering. Originality/value The case studies and the random instance generator are made publicly available to foster further research on the problem of pre-positioning relief supplies and humanitarian logistics in general.

scholarly journals Eco-efficient management of a feeding system in an automobile assembly-line

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Montserrat-Ana Miranda ◽  
María Jesús Alvarez ◽  
Cyril Briand ◽  
Matías Urenda Moris ◽  
Victoria Rodríguez
Keyword(s):  
Assembly Line ◽  
Programming Model ◽  
Optimal Solution ◽  
Optimization Procedure ◽  
Green Manufacturing ◽  
Mixed Integer ◽  
Production Plant ◽  
Optimization Strategy ◽  
Content Type ◽  
Automobile Assembly

Purpose This study aims to reduce carbon emissions and costs in an automobile production plant by improving the operational management efficiency of a serial assembly line assisted by a feeding electric tow vehicle (ETV). Design/methodology/approach A multi-objective function is formulated to minimize the energy consumption of the ETV from which emissions and costs are measured. First, a mixed-integer linear programming model is used to solve the feeding problem for different sizes of the assembly line. Second, a bi-objective optimization (HBOO) model is used to simultaneously minimize the most eco-efficient objectives: the number of completed runs (tours) by the ETV along the assembly line, and the number of visits (stops) made by the ETV to deliver kits of components to workstations. Findings The most eco-efficient strategy is always the bi-objective optimal solution regardless of the size of the assembly line, whereas, for single objectives, the optimization strategy differs depending on the size of the assembly line. Research limitations/implications Instances of the problem are randomly generated to reproduce real conditions of a particular automotive factory according to a previous case study. The optimization procedure allows managers to assess real scenarios improving the assembly line eco-efficiency. These results promote the implementation of automated control of feeding processes in green manufacturing. Originality/value The HBOO-model assesses the assembly line performance with a view to reducing the environmental impact effectively and contributes to reducing the existent gap in the literature. The optimization results define key strategies for manufacturing industries eager to integrate battery-operated motors or to address inefficient traffic of automated transport to curb the carbon footprint.

scholarly journals Risk interaction identification in international supply chain logistics

2018 ◽  
Vol 38 (2) ◽  
pp. 372-389 ◽  
Author(s):  
Dong-Wook Kwak ◽  
Vasco Sanchez Rodrigues ◽  
Robert Mason ◽  
Stephen Pettit ◽  
Anthony Beresford
Keyword(s):  
Risk Management ◽  
Supply Chain ◽  
Risk Analysis ◽  
Supply Chains ◽  
Analysis Model ◽  
Content Type ◽  
Risk Elements ◽  
Supply Chain Logistics ◽  
Holistic Understanding ◽  
Level 2

Purpose International supply chains can be severely disrupted by failures in international logistics processes. Therefore, an understanding of international logistics risks, or causes of failure, how these may interact with each other and how they can be mitigated are imperatives for the smooth operation of international supply chains. The purpose of this paper is to specifically investigate the interactions between international logistics risks within the prevailing structures of international supply chains and highlights how these risks may be inter-connected and amplified. A new dynamic supply chain logistics risk analysis model is proposed which is novel as it provides a holistic understanding of the risk event interactivity. Design/methodology/approach The paper applies interpretive structural modelling to data collected from a survey of leading supply chain practitioners, in order to analyse their perspectives of risk elements and interactions. The risk elements and their contextual relationship were derived empirically through the use of focus groups and subsequent Delphi study. The two stages of the research rely on experts’ views on risk events and clusters and the level of interactions among those clusters. Findings A key finding of this research is that supply chain practitioner’s perception of risk consists of inter-connected four levels: value streams risks; information and relationship risks; risks in international supply chain activities; and external environment. In particular, since level 2 risk creates feedback loops of risks, risk management at level 2 can dampen the amplification effect and the strength of the interactions. Practical implications Several managerial implications are drawn. First, the research guides managers in the identification and evaluation of risk events which can impact the performance of their international logistics supply chain operations. Second, evidence is presented that supports the proposition that the relationships with trading partners and LSPs, and the degree of logistics information exchange, are critical to prevent, or at least mitigate, logistics risks which can substantially affect the responsiveness of the international supply chain. Originality/value The main contribution to knowledge that this study offers to the literature on supply chain risk management is the development of a supply chain logistics risk analysis model which includes both risk elements and interactions. The research demonstrates the importance of taking into account risk interactions in the process of identification and evaluation of risk events.

A risk analysis model for mining accidents using a fuzzy approach based on fault tree analysis

2018 ◽  
Vol 31 (4) ◽  
pp. 577-594 ◽  
Author(s):  
Fatma Yasli ◽  
Bersam Bolat
Keyword(s):  
Risk Analysis ◽  
Management Strategies ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Fuzzy Approach ◽  
Analysis Model ◽  
Basis Risk ◽  
Tree Analysis ◽  
Content Type ◽  
Essential Components

Purpose Risk analysis is a critical investigation field for many sectors and organizations to maintain the information management reliable. Since mining is one of the riskiest sectors for both workers and management, comprehensive risk analysis should be carried out. The purpose of this paper is to explore comprehensively the undesired events that may occur during a particular process with their main reasons and to perform a risk analysis for these events, by developing a risk analysis methodology. For performing risk analysis, discovering and defining the potential accidents and incidents including their root causes are important contributions of the study as distinct from the related literature. The fuzzy approach is used substantially to obtain the important inferences about the hazardous process by identifying the critical risk points in the processes. In the scope of the study, the proposed methodology is applied to an underground chrome mine and obtaining significant findings of mining risky operations is targeted. Design/methodology/approach Fault tree analysis and fuzzy approach are used for performing the risk analysis. When determining the probability and the consequences of the events which are essential components for the risk analysis, expressions of the heterogeneous expert group are considered by means of the linguistic terms. Fault tree analysis and fuzzy approach present a quiet convenience solution together to specify the possible accidents and incidents in the particular process and determine the values for the basis risk components. Findings This study primarily presents a methodology for a comprehensive risk analysis. By implementing the proposed methodology to the underground loading and conveying processes of a chrome mine, 28 different undesired events that may occur during the processes are specified. By performing risk analysis for these events, it is established that the employee’s physical constraint while working with the shovel in the fore area, the falling of materials on employees from the chute and the scaling bar injuries are the riskiest undesired events in the underground loading and conveying process of the mine. Practical implications The proposed methodology provides a confidential and comprehensive method for risk analysis of the undesired events in a particular process. The capability of fault tree analysis for specifying the undesired events systematically and the applicability of fuzzy approach for converting the experts’ linguistic expressions to the mathematical values provide a significant advantage and convenience for the risk analysis. Originality/value The major contribution of this paper is to develop a methodology for the risk analysis of a variety of mining accidents and incidents. The proposed methodology can be applied to many production processes to investigate the dangerous operations comprehensively and find out the efficient management strategies. Before performing the risk analysis, determining the all possible accidents and incidents in the particular process using the fault tree analysis provides the effectiveness and the originality of the study. Also, using the fuzzy logic to find out the consequences of the events with experts’ linguistic expressions provides an efficient method for performing risk analysis.

The economic order quantity model with inspection policy of zero-defect single sampling

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahdi Nakhaeinejad
Keyword(s):  
Sample Size ◽  
Inventory Management ◽  
Optimal Solution ◽  
Random Variable ◽  
Solution Procedure ◽  
Order Quantity ◽  
Content Type ◽  
Numerical Examples ◽  
Proposed Model ◽  
Inspection Policy

PurposeThis paper proposes a new inventory model with inspection policy because in practice the received orders may contain non- conforming (NC) items. So, a buyer who receive an order from a supplier should use an inspection policy.Design/methodology/approachThe inspection policy is assumed to be zero-defect single sampling. Under this policy a lot is accepted only if no defect has been identified in the inspected sample. The fraction of NC is assumed to be a random variable following a Binomial distribution and the number of NC items detected by inspection assumed to be a random variable, which follows a hypergeometric distribution. Order quantity and sample size are the two decision variables. A solution procedure is presented for the proposed model. The proposed procedure presents the optimal solution.FindingsNumerical examples presented to illustrate the procedure outlined for the proposed model and its applicability. The results of numerical examples and comparing them with traditional EOQ model reveal that by the proposed model, the buyer could reduce total cost that shows the efficiency and validity of the proposed model.Originality/valueThe novelty of this paper is the new proposed model that considers inspection policy in inventory management. The proposed model determines sample size as well as order quantity to consider both subject of inventory management and quality control, simultaneously.

New Classification of Security Requirements for Quantitative Risk Assessment

2018 ◽  
pp. 100-117
Author(s):  
Neila Rjaibi ◽  
Latifa Ben Arfa Rabai
Keyword(s):  
Risk Analysis ◽  
Large Scale ◽  
Financial Analysis ◽  
Objective Assessment ◽  
Research Work ◽  
Quantitative Risk Assessment ◽  
Security Requirements ◽  
Analysis Model ◽  
Security Applications ◽  
E Learning

Objective assessment metrics are continuously recommended and a financial analysis of the risk is required in order to justify the security improvements. It is, thus, critically important to validate the security applications as trustworthy and to generalize this research work to other systems. The chapter addresses firstly the problem of quantifying the security of large scale systems, originally the level of e-learning systems. The risk analysis model considers the variability between the system's stakeholders, the requirements, the components and the security attacks. But, in case of large systems, other security challenges are crucially important to be considered. Indeed, our risk analysis model is strengthened to include the development of new requirements classification.

Dimensioning a recovery boiler furnace using mathematical optimization

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 119-129 ◽  
Author(s):  
VILJAMI MAAKALA ◽  
PASI MIIKKULAINEN
Keyword(s):  
Radial Basis Function Network ◽  
High Capacity ◽  
Mathematical Optimization ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Performance Criteria ◽  
Boiler Furnace ◽  
Starting Point ◽  
Recovery Boiler ◽  
Base Design

Capacities of the largest new recovery boilers are steadily rising, and there is every reason to expect this trend to continue. However, the furnace designs for these large boilers have not been optimized and, in general, are based on semiheuristic rules and experience with smaller boilers. We present a multiobjective optimization code suitable for diverse optimization tasks and use it to dimension a high-capacity recovery boiler furnace. The objective was to find the furnace dimensions (width, depth, and height) that optimize eight performance criteria while satisfying additional inequality constraints. The optimization procedure was carried out in a fully automatic manner by means of the code, which is based on a genetic algorithm optimization method and a radial basis function network surrogate model. The code was coupled with a recovery boiler furnace computational fluid dynamics model that was used to obtain performance information on the individual furnace designs considered. The optimization code found numerous furnace geometries that deliver better performance than the base design, which was taken as a starting point. We propose one of these as a better design for the high-capacity recovery boiler. In particular, the proposed design reduces the number of liquor particles landing on the walls by 37%, the average carbon monoxide (CO) content at nose level by 81%, and the regions of high CO content at nose level by 78% from the values obtained with the base design. We show that optimizing the furnace design can significantly improve recovery boiler performance.

Computational contact mechanics analysis of laterally graded orthotropic half-planes

2017 ◽  
Vol 14 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Onur Arslan
Keyword(s):  
Contact Mechanics ◽  
Solution Method ◽  
Solution Procedure ◽  
Engineering Applications ◽  
Linear Solution ◽  
Content Type ◽  
Analytical Technique ◽  
Computational Contact Mechanics ◽  
Mechanics Analysis ◽  
Contact Response

Purpose Frictional sliding contact problems between laterally graded orthotropic half-planes and a flat rigid stamp are investigated. The presented study aims at guiding engineering applications in the prediction of the contact response of orthotropic laterally graded members. Design/methodology/approach The solution procedure is based on a finite element (FE) approach which is conducted with an efficient FE analysis software ANSYS. The spatial gradations of the orthotropic stiffness constants through the horizontal axis are enabled utilizing the homogeneous FE approach. The Augmented Lagrangian contact algorithm is used as an iterative non-linear solution method in the contact analysis. Findings The accuracy of the proposed FE solution method is approved by using the comparisons of the results with those computed using an analytical technique. The prominent results indicate that the surface contact stresses can be mitigated upon increasing the degree of orthotropy and positive lateral gradations. Originality/value One can infer from the literature survey that, the contact mechanics analysis of orthotropic laterally graded materials has not been investigated so far. In this study, an FE method-based computational solution procedure for the aforementioned problem is addressed. The presented study aims at guiding engineering applications in the prediction of the contact response of orthotropic laterally graded members. Additionally, this study provides some useful points related to computational contact mechanics analysis of orthotropic structures.

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