| 1. |
- Ahmadi, Alireza, et al.
(författare)
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Risk of operational consequences of aircraft system failure
- 2010
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Ingår i: International Journal of Performability Engineering. - 0973-1318. ; 6:2, s. 149-158
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper is to describe a methodology for identifying different operational consequences and associated costs caused by aircraft system failure, in order to facilitate and enhance the capability of taking correct and efficient decisions when analyzing the cost-effectiveness of maintenance tasks. The paper focuses on the operational consequences of failures that lead to delay. To identify the operational consequences of aircraft system failures, Empirical studies of possible scenarios involving aircraft failures and their operational consequences for a commercial airline have been performed. Empirical data were extracted through document studies and interviews, guided by the application of an Event Tree Analysis (ETA). In order to effectively utilize the knowledge of field experts in the assessment process, a pairwise comparison technique was adopted for quantifying the contribution of different factors to the operational. The work was performed together with experienced practitioners from both an aircraft manufacturer and commercial airlines, which contributed to a continuous verification of the outcome of the study.The study shows that the proposed methodology based on ETA and pairwise comparison can be used to identify and quantify the cost of operational consequences of failures in aircraft operation, when there is no sufficient and reliable data.
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| 2. |
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| 3. |
- Baas, Leo
(författare)
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Dissemination Models for Cleaner Production and Industrial Ecology
- 2005
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Ingår i: International Journal of Performability Engineering. - : RAMS Consultants. - 0973-1318. ; 1:1, s. 89-99
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Tidskriftsartikel (refereegranskat)abstract
- Cleaner Production and Industrial Ecology are challenging new preventive concepts that can improve the environmental and economic performance of industry. In this paper, the author sketches the conditions to challenge the experienced reluctance to change routines in many dissemination projects of these concepts. Organizational learning processes are needed to go beyond limited results such as some good housekeeping practices and waste exchange links.A dilemma for the dissemination of new concepts in general is that pilot studies never meet the full conditions that are needed. The disseminator is often restricted through resistance to change and many organisational management obstacles. The organisation that is willing to co-operate with an assessment, is often not really interested in the implementation of the results. The funds for research are bounded to the limits of the vision of the funding public or private organisations.In this article a change process that might generate more radical approaches, is promoted. The steps of this dissemination process within and between organizations are: 1. Bringing information about a new concept for the start of a process of awareness-raising and commitment building; 2. After that, educating the concept to provide the knowledge for the assessments of the concept and strategic discussions in interaction processes with the key-actorswithin and between organizations to generate a basis for implementation; 3. Evaluating the learning processes to stimulate continuous improvement programmes; 4. The above-mentioned actions can be better embedded in organizations when asurroundings and an organizational analysis for the dissemination of the new concept is performed and the results are included in the approach.
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| 4. |
- Barabady, Javad, et al.
(författare)
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Reliability Characteristics Based Maintenance Scheduling: A Case Study of a Crushing Plant
- 2007
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Ingår i: International Journal of Performability Engineering. - : RAMS Consultants. - 0973-1318. ; 3:3, s. 319-328
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Tidskriftsartikel (refereegranskat)abstract
- The cost of maintenance is too high in mining industry to ignore. This is mainly due to poor understanding of the maintenance process which is greatly influenced by the reliability characteristics of the operating system. The paper introduces an approach for maintenance scheduling of a mining system based on reliability analysis which is divided into two parts. The first part introduces a methodology for optimal maintenance scheduling based on analysis of maintenance data in the form of time-between-failure and time-to-repair distributions. In the second part, we present a case study from Jajarm Bauxite Mine in Iran to illustrate the applicability of the maintenance scheduling model.
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| 5. |
- Block, Jan, et al.
(författare)
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Fleet-Level Reliability Analysis of Repairable Units: A Non-Parametric Approach using the Mean Cumulative Function
- 2013
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Ingår i: International Journal of Performability Engineering. - 0973-1318. ; 9:3, s. 333-344
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Tidskriftsartikel (refereegranskat)abstract
- Complex technical systems are normally repaired rather than replaced when they fail. It is often desirable to analyze the reliability characteristics of these systems based on data generated in a customer use environment, in order to assess the reliability, frequency of failure or other parameters which may be influenced by the systems’ age and usage. Despite the advantages of continuously analyzing reliability data to be able to improve the maintenance programme continuously, methods such as parametric and non-parametric analysis are often ignored due to a belief that the mean time between failures (MTBF) is sufficient to describe the reliability pattern of repairable units. This paper describes the use of the mean cumulative function (MCF) and linear estimates based on the recurrence rate to predict the expected number of failures in the future. Reliability data from two repairable units are used to verify the procedure and comparison. The empirical data used in the paper is based on field data gathered during the operational life of the Swedish military aircraft system FPL 37 Viggen from 1977 to 2006, which essentially is the whole life cycle of the system.
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| 6. |
- Block, Jan, et al.
(författare)
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Fleet-level Reliability of Multiple Repairable Units: a Parametric Approach using the Power Law Process
- 2014
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Ingår i: International Journal of Performability Engineering. - 0973-1318. ; 10:3, s. 239-250
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Tidskriftsartikel (refereegranskat)abstract
- The application of parametric reliability analysis methods for repairable units, such as Power law process, is quite clear and straightforward for a single repairable unit. However, in practice, the analyst needs to know the reliability characteristics of units at a fleet level. The application of parametric reliability analysis methods at the fleet level, even if it is limited in scope, is quite complex. The aim of this paper is to describe the use of the power law process for multiple repairable units with differing reliability characteristics, to predict the expected number of failures at fleet level. The empirical data used in the paper are based on field data gathered during the operational life of two types of multi repairable units used in the Swedish military aircraft system FPL 37 Viggen from 1977 to 2006. The paper performs the trend test using TTT-based MIL-HDBK-189 and Laplace tests, and assesses the equality of shape-parameters for the intensity function of the power law process for multiple units. Estimation of the scale- and shape-parameters using maximum likelihood estimation is also performed. The parametric approach using power law process was found to yield relatively accurate estimations of number of failures, compared to empirical data
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| 7. |
- Candell, Olov, et al.
(författare)
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Development of information system for e-maintenance solutions within the aerospace industry
- 2011
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Ingår i: International Journal of Performability Engineering. - 0973-1318. ; 7:6, s. 583-592
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Tidskriftsartikel (refereegranskat)abstract
- Maintenance and support providers to modern aircraft need to manage an increasing amount of information generated by growing system complexity and stakeholder requirements. This introduces new risks in the information management process and makes traditional information services and systems inadequate. However, recent advancements in information and communication technology (ICT) have contributed to the emerging approach of e-Maintenance, which forms an important building block to achieve the desired information logistics. e-Maintenance enables remote and real time maintenance, and includes; collection, monitoring, analysis and distribution of data and information as decision-support to stakeholders of the maintenance and support processes, independent of organization or geographical location, 24 hours a day and 7 days a week (24/7). This paper describes a proposed development of information products by linking theories to practical methodologies and tools (e.g., Quality Function Deployment, QFD) through the development of a demonstrator of a stakeholder-based information product in the context of a modern combat aircraft. Read more about November 2011 P8 - Development of Information System for e-Maintenance Solutions within the Aerospace Industry by www.ijpe-online.com
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| 8. |
- Chattopadhyay, Gopi, et al.
(författare)
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Parameter estimation for rail degradation model
- 2009
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Ingår i: International Journal of Performability Engineering. - 0973-1318. ; 5:2, s. 119-130
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Tidskriftsartikel (refereegranskat)abstract
- Wear and fatigue in rails are major contributors of rail degradation depending on operational conditions, track, characteristics of bogie type, Million Gross Tonnes (MGT), curvature, traffic type and environmental conditions. Estimation of parameter for failure models is necessary for accurate prediction of expected number of rail defects over a period of time based on MGT of traffic and operating conditions for developing cost effective maintenance strategies. This paper focuses on collection and analysis of field data over a period of time for estimation of parameter for modelling rail life.
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| 9. |
- Eker, O.F., et al.
(författare)
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SVM based diagnostics on railway turnouts
- 2012
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Ingår i: International Journal of Performability Engineering. - 0973-1318. ; 8:3, s. 289-298
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Tidskriftsartikel (refereegranskat)abstract
- Railway turnout systems are one of the most critical pieces of equipment in railway infrastructure. Early identification of failures in turnout systems is important to obtain increased availability and safety, and reduced operating and support costs. This paper aims to develop a method to identify 'drive-rod out-of-adjustment' failure mode, one of the most frequently observed failure modes. Support Vector Machine (SVM) with Gaussian kernel is used for diagnosis. In addition, the results of feature selection with statistical t-test and feature reduction with principal component analysis (PCA) are compared in the paper
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| 10. |
- Flammini, Francesco, Senior Lecturer, 1978-
(författare)
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Model-based analysis of 'k out of m' correlation techniques for diverse redundant detectors
- 2013
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Ingår i: International Journal of Performability Engineering. - : RAMS Consultants. - 0973-1318. ; 9:5, s. 551-560
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Tidskriftsartikel (refereegranskat)abstract
- Sensors are widespread in applications ranging from environmental monitoring to distributed surveillance for physical security. Novel protocols and appropriate topologies enable large networks of cheap smart-sensors with the main objective of providing pervasiveness and resilience. In this paper we provide a model-based analysis of a 'k-out-of-m' ('KooM') voting approach which can be used to correlate data coming from heterogeneous event detecting devices. The approach is based on the assumption of diverse redundancy on sensor technologies. The Bayesian Network formalism is employed to perform the analysis. The results show that by choosing appropriate correlation logics an optimal trade-off can be achieved among probability of detection, false alarm rate, availability and robustness against spoofing attempts, depending on the specific application. Furthermore, it will be shown that majority voting on detector outputs allows for a high cost effectiveness in obtaining performance improvements. © RAMS Consultants.
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