Cost Of Corrective Actions Research Articles

Optimization the reliability of emergency safety barriers based on the subjective safety analysis and evidential reasoning theory. Case study

PurposeThis study aims to improve the reliability of emergency safety barriers by using the subjective safety analysis based on evidential reasoning theory in order to develop on a framework for optimizing the reliability of emergency safety barriers.Design/methodology/approachThe emergency event tree analysis is combined with an interval type-2 fuzzy-set and analytic hierarchy process (AHP) method. In order to the quantitative data is not available, this study based on interval type2 fuzzy set theory, trapezoidal fuzzy numbers describe the expert's imprecise uncertainty about the fuzzy failure probability of emergency safety barriers related to the liquefied petroleum gas storage prevent. Fuzzy fault tree analysis and fuzzy ordered weighted average aggregation are used to address uncertainties in emergency safety barrier reliability assessment. In addition, a critical analysis and some corrective actions are suggested to identify weak points in emergency safety barriers. Therefore, a framework decisions are proposed to optimize and improve safety barrier reliability. Decision-making in this framework uses evidential reasoning theory to identify corrective actions that can optimize reliability based on subjective safety analysis.FindingsA real case study of a liquefied petroleum gas storage in Algeria is presented to demonstrate the effectiveness of the proposed methodology. The results show that the proposed methodology provides the possibility to evaluate the values of the fuzzy failure probability of emergency safety barriers. In addition, the fuzzy failure probabilities using the fuzzy type-2 AHP method are the most reliable and accurate. As a result, the improved fault tree analysis can estimate uncertain expert opinion weights, identify and evaluate failure probability values for critical basic event. Therefore, suggestions for corrective measures to reduce the failure probability of the fire-fighting system are provided. The obtained results show that of the ten proposed corrective actions, the corrective action “use of periodic maintenance tests” prioritizes reliability, optimization and improvement of safety procedures.Research limitations/implicationsThis study helps to determine the safest and most reliable corrective measures to improve the reliability of safety barriers. In addition, it also helps to protect people inside and outside the company from all kinds of major industrial accidents. Among the limitations of this study is that the cost of corrective actions is not taken into account.Originality/valueOur contribution is to propose an integrated approach that uses interval type-2 fuzzy sets and AHP method and emergency event tree analysis to handle uncertainty in the failure probability assessment of emergency safety barriers. In addition, the integration of fault tree analysis and fuzzy ordered averaging aggregation helps to improve the reliability of the fire-fighting system and optimize the corrective actions that can improve the safety practices in liquefied petroleum gas storage tanks.

A robust rolling horizon framework for empty repositioning

Naturally imbalanced freight flows force transportation service providers to reposition empty resources. When constructing empty repositioning plans, the cost of repositioning empty resources needs to be weighed against the cost of corrective actions in case of unavailable resources. This is especially challenging given the uncertainty of future demand. We design and implement a robust rolling horizon framework for constructing effective empty repositioning plans. An extensive computational study demonstrates the benefits of explicitly accounting for uncertainty in future demand by using robust optimization, and pragmatically controlling the level of conservatism in hedging against this uncertainty. We also investigate practical strategies for reducing the complexity of managing the repositioning of empty resources in transportation service networks covering huge geographic areas.

Prioritizing health, safety and environmental hazards by integrating risk assessment and analytic hierarchy process techniques in solid waste management facilities

The aim of this research was to assess and prioritize risk levels of health, safety, and environmental (HSE) hazards in solid waste management facilities of Tehran, Iran. The risk of HSE hazards was assessed using Fine-Kinney and environmental failure mode and effects analysis (EFMEA) methods and then the high-risk hazards were prioritized for implementing corrective actions by analytic hierarchy process (AHP) considering six criteria of (1) probability of occurrence, (2) severity of consequences, (3) simultaneous HSE effects, and (4-6) feasibility, effectiveness, and cost of corrective actions. A total number of 485 HSE hazards were identified, of which 78% were health and safety hazards and 22% were environmental hazards. The proportions of the transfer and transport, material recovery and composting facilities and landfill sites in the identified hazards were 21%, 38%, and 41%, respectively. Based on the AHP method, the leading hazards in the transfer and transport, material recovery and composting facilities, and landfill sites were exposure to bioaerosol in carwash facilities, exposure to bioaerosols and odor/volatile organic compounds (VOCs) in manual waste separation, and leachate spills in the former landfill site, respectively. This study showed that the hybrid method was an appropriate and reliable tool to prioritize HSE hazards.

Managing uncertainty to deliver complex development wells

SummaryManaging seismic depth uncertainty is a key consideration in placing horizontal development wells into thin reservoir targets. Seismic depth uncertainty has the potential to erode project value through missed reservoir (late landing or reservoir exits) and/or the cost of corrective actions (e.g. sidetracks). The placement of Laverda Canyon development wells in 2018 utilised a 30 Hz full waveform inversion velocity model and deep directional resistivity data in combination with a near real-time depth update process to optimise well placement.Utilising these methods resulted in a significant reduction in seismic depth uncertainty which culminated in the final Laverda Canyon development well (LAV04WI) being successfully geosteered for ~ 2,200 m within a 10-15 m thick reservoir with only one reservoir exit.

Transmission Network Investment With Distributed Energy Resources and Distributionally Robust Security

Distributed energy resources (DER) have the potential to significantly contribute to network security and hence release latent capacity of existing transmission assets. In this context, we propose a distributionally robust approach to network security in order to recognize the limited data and knowledge associated with the underlying process behind the realization of system contingencies within the transmission expansion planning (TEP) problem, and thus determine the optimal portfolio of DER services necessary to displace, in a secure fashion, inefficient network investments. To do so, we propose a two-stage optimization model where the first stage determines the transmission expansion plan and the scheduling of DER post-contingency services in coordination with further corrective control measures such as generation reserves. The second stage minimizes the expected cost of corrective actions under various contingencies. Through various case studies, we demonstrate the benefits of security services provided by DER and the advantages of our proposed distributionally robust approach (where outage rates are assumed ambiguous) against alternative $n-K$ security and stochastic approaches, where outage rates are either ignored or assumed fully known, respectively.

Robust Solution Approach for the Dynamic and Stochastic Vehicle Routing Problem

The dynamic and stochastic vehicle routing problem (DSVRP) can be modelled as a stochastic program (SP). In a two-stage SP with recourse model, the first stage minimizes the a priori routing plan cost and the second stage minimizes the cost of corrective actions, performed to deal with changes in the inputs. To deal with the problem, approaches based either on stochastic modelling or on sampling can be applied. Sampling-based methods incorporate stochastic knowledge by generating scenarios set on realizations drawn from distributions. In this paper we proposed a robust solution approach for the capacitated DSVRP based on sampling strategies. We formulated the problem as a two-stage stochastic program model with recourse. In the first stage the a priori routing plan cost is minimized, whereas in the second stage the average of higher moments for the recourse cost calculated via a set of scenarios is minimized. The idea is to include higher moments in the second stage aiming to compute a robust a priori routing plan that minimizes transportation costs while permitting small changes in the demands without changing solution structure. Additionally, the approach allows managers to choose between optimality and robustness, that is, transportation costs and reconfiguration. The computational results on a generic dynamic benchmark dataset show that the robust routing plan can cover unmet demand while incurring little extra costs as compared to the preplanning. We observed that the plan of routes is more robust; that is, not only the expected real cost, but also the increment within the planned cost is lower.

A Study on Optimization of Nonconformities Management Cost in the Quality Management System (QMS) of Small-sized Enterprise of the Construction Industry

The article discusses problems of forming an effective corrective action plan to address identified nonconformities. The author proposes to consider two types of costs; the costs of the correction of nonconforming product which appeared as a result of nonconformity, and the costs of corrective actions aimed at addressing the causes of the nonconformities. In this study the original ranking algorithm of corrective actions is described. The purpose of the algorithm is to minimize the potential costs of elimination of the potential nonconforming products, specifically when there are limitations on the funds for corrective actions.

Real-Time Dispatchability of Bulk Power Systems With Volatile Renewable Generations

The limited predictability and high variability of renewable generations has brought significant challenges on the real-time operation of bulk power systems. This paper proposes the concept of real-time dispatchability (RTDA) of power systems with variable energy resources, which focuses on investigating the impact of operating constraints and the cost of corrective actions on the flexibility of real-time dispatch. RTDA is the largest region in the uncertainty space, such that all the elements in it will not cause infeasibility while deploying a corrective action. This paper proposes a closed polyhedral form of RTDA. Moreover, an adaptive constraint generation algorithm is proposed to compute the boundaries of RTDA. Three potential applications are suggested. Case studies on the IEEE 118-bus system illustrate the RTDA concept and demonstrate the validity and efficiency of the proposed method in practical applications.

Cost evaluation of airline maintenance investigation-triggering methods

A reliable investigation-triggering mechanism is critical for airlines in managing aircraft fleet reliability. This study developed a simulation model to evaluate the performance of various investigation-triggering mechanisms in various scenarios of aircraft fleet reliability. Factors that affect performance include flight delay costs, investigation costs, the costs of corrective actions, the accuracy of investigations, the effectiveness of corrective actions, and the monthly improvement rate. Nine investigation-triggering mechanisms were evaluated. The simulation results show that the monthly improvement rate significantly influences performance. The subject airline’s original investigation-triggering mechanism is not outstanding in most scenarios. This study recommends two of the nine investigation-triggering mechanisms for airlines when they select investigation-triggering mechanisms in various scenarios. Thus, useful guidance for adjusting airlines’ investigation-triggering mechanisms can be effectively provided.

A multiple objective approach to scheduling the preventive maintenance of modular aircraft components

Preventive maintenance (or overhaul) is crucial for military aircraft operations because it dictates the mission readiness level and aircraft operating costs. For example, preventive maintenance not only improves the lifetime aircraft reliability/safety by avoiding unexpected equipment failure and downtime, but it also enhances the efficiency of managing spare-part by planning the replacements and replenishment of spare parts within the predetermined time interval. Despite such benefits, preventive maintenance may not be economical, unless its schedule is determined in such a way that its overall preventive maintenance costs including costs associated with the purchase of spare modules is less than the total costs of corrective actions including downtime/idle costs, repair costs, and mission failures. With that in mind, we propose a dynamic goal programming (GP) model that aims at determining the optimal number of spare modules, while meeting the scheduled due dates for preventive maintenance under budget constraints.

An integrated structural framework to cost-based FMECA: The priority-cost FMECA

The Failure Mode, Effects and Criticality Analysis (FMECA) methodology is a widely recognized tool for the study and reliability analysis of a design or process. Many authors in the field have emphasized the usefulness of this particular method as well as its limitations. In particular, there are two main criticisms regarding the Risk Priority Number (RPN) method of calculation and the extreme difficulty in considering the variable of the corrective action cost in the analysis. The main scope of this work is to present a new integrated approach, named priority-cost FMECA (PC-FMECA), in order to exceed these limits. Making reference to a paper by Braglia [MAFMA: multi-attribute failure modes analysis. Int J Qual Reliab Manage 2000; 17(9)], this study proposes a method which allows for the calculation of a new RPN and the introduction of the concept of Profitability taking into consideration the corrective action cost. The study is divided in three fundamental phases: critical analysis of the FMECA model, proposal and development of the PC-FMECA and presentation of an implemented case study in the automotive field.

Estimating the costs of corrective action at land disposal facilities

AbstractThe U.S. Environmental Protection Agency (EPA) has proposed regulations that would require corrective action (e.g., soil excavation and groundwater removal and treatment) at municipal solid waste landfills (MSWLFs) and hazardous waste treatment, storage, and disposal facilities (TSDFs). This paper presents an overview of the proposed corrective action regulations, and discusses their relationship to proposed or existing closure and post‐closure care regulations. The paper then presents estimated corrective action cost curves for various MSWLF scenarios defined by landfill area, average waste thickness, and the presence or absence of a clay liner. The paper finally illustrates the economic benefits of sound closure and postclosure care by comparing estimated costs of corrective action to estimated costs of closure and postclosure care at MSWLFs.

1990 Thermal Remediation Industry Contractor Survey

The treatment of soil contaminated with organics and inorganics is becoming a major industry in the United States and Europe. The soil cleanup bill for the United States could run as high as $200 to $300 billion over the next 30 to 40 years. European soil cleanup costs could run as high as $130 billion.1 The types of sites in the United States that will require soil treatment can be broken down into the following categories: •CERCLA (Superfund) Actions•RCRA Corrective Actions•RCRA Closures•Underground Storage Tanks•Real Estate Transfers•Spill Clean-ups. The cleanup of sites in each of these categories, with the exception of the Real Estate Transfer category, is being driven by different sets of Federal regulations. Real Estate Transfer type regulations were first instituted in New Jersey and have now been promulgated in a number of other states. The eventual cleanup cost for the Superfund sites will be close to $200 billion. Estimated costs for the industrial sector Superfund are $25 to $50 billion and the estimated cost for the Department of Energy sites is over $150 billion.2 An early RCRA Corrective Action cleanup estimate is $25 billion.3 This estimate may well be low, however, since the permitting, cleanup and delisting criteria are still not clearly defined. The EPA’s RCRA Corrective Action cost estimate is $7.4 billion. However, the Office of Management and Budget feels that this estimate is low.4 The potential magnitude of the cleanup costs has resulted in the development and implementation of many technologies for the decontamination of soils. Of the available remedial technologies, thermal treatment has perhaps had the most field testing. The purpose of this paper is to focus on the full scale site remediations which have been or are being conducted using thermal processing equipment. Projects which have been completed, are on-going, or have been contracted for, through January of 1990 are described.

The Effects of Attributions and Costs of Corrective Actions on Leaders' Implementation of Control Policy: An extension of the Attributional Model of Leadership

This study was conducted to investigate the manner in which attributions and costs of corrective actions affect leaders' implementation of control policy. It was predicted that leaders would be less likely to adhere to organizational control policy when rule infractions were due to external factors and when the rule violator was a high performer. In addition, the effects of leaders' orientation toward winning on corrective actions were investigated. Eighty college coaches were divided into two groups on the basis of personal characteristic of orientation toward winning (high vs. low). Each coach responded to a scenario that described a curfew violation committed by either a star or a substitute player. The infraction was caused by either internal or external factors. Analyses indicated that leaders were more willing to circumvent the organization's control policy when the rule infraction was caused by external factors and that this tendency was more pronounced with low-orientation toward winning (OTW) leaders. The results extend from Green and Mitchell (1979) attributional model of leadership and confirm the importance of personal characteristics in control decisions.