Browsing by Author "Conradie, P. D. F."

Now showing 1 - 4 of 4
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    Exploring critical failure modes in the rail environment and the consequential costs of unplanned maintenance
    (CIE & SAIIE, 2012) Conradie, P. D. F.; Treurnicht, N. F.
    This study explores in-service failure modes for rolling stock in the rail environment, identifies the most critical failures and explores the consequential cost of these failure modes. Rolling stock is maintained according to maintenance plans with a major goal being the prevention of in-service failures, but due to the nature of the equipment not all failures can be prevented. In-service failures normally result in train delays or the cancellations of trains not only disrupting commuter services but also causing financial losses. The typical failures of rolling stock are analysed using data from the facility maintenance management system. The critical failure modes are identified and classified according to cause, severity, consequence and frequency parameters. A decision model is employed to classify the criticality of the failure modes. The most prominent critical failure modes are analysed to determine root causes, to conclude the investigation. Areas are identified where the focus of future investigation and planned maintenance will have the most significant impact.
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    Quantifying system reliability in rail transportation in an ageing fleet environment
    (SAIIE, 2015) Conradie, P. D. F.; Fourie, Cornelius; Vlok, Pieter; Treurnicht, Nico
    In recent years the management of physical assets has become increasingly important, especially in asset-intensive organisations. This article presents an approach to quantifying the reliability of rolling stock assets in the rail environment, making use of failure statistics. Failure distributions and the interdependency of different systems are used to determine the impact of component failures on overall system reliability, and to determine the reliability of individual train sets. Recommendations about the future planning of maintenance are included in the article.
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    Quantifying system reliability in rail transportation in an aging fleet environment
    (Stellenbosch : Stellenbosch University, 2015-03) Conradie, P. D. F.; Oosthuizen, G. A.; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.; Conradie, Pieter Daniel Francois
    ENGLISH ABSTRACT: In recent years, the management of physical assets has become increasingly important, even more so, in asset intensive organisations. This research work presents an overall approach to quantify reliability of rolling stock assets in the rail environment. The current maintenance management system in the case studied is over-reliant on cancellations and delays as reliability measure. The objectives of this study were, therefore, to develop a scientific approach to quantify the reliability of the rolling stock fleet and to develop a maintenance planning model based on system reliability. The research methodology followed made use of failure statistics, failure distributions and the interdependence of different systems to determine the impact of component failures on the overall system reliability. This could then be used to determine the reliability of individual train sets in order to better understand their performance. The reliability measure could be used for predicting component and train set failures as well as to better understand the contribution of maintenance towards reliability, hence the term Reliability Based Maintenance. The model, validated with real data, illustrates how the reliability measure can be used to determine maintenance intervals of different train sets. Based on the results, recommendations are made in relation to future planning of the maintenance strategy.
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    A risk and cost management analysis for changes during the construction phase of a project
    (South African Institution of Civil Engineering, 2016) Schoonwinkel, S.; Fourie, C. J.; Conradie, P. D. F.
    In civil construction projects, changes are inevitable, impacting projects in terms of cost, time and quality. It is nevertheless expected of project managers to effectively manage the impacts of project changes, and to complete the project within the project constraints, despite such changes. This article explores the impact of changes on a project by comparing the findings from a South African case study to the impact of changes found in literature. The article further investigates how consulting engineers in the Western Cape deal with changes in projects, and how cost risk management is performed during changes. The findings are startling and expose the shortage of necessary skills and competencies within project management. A fresh approach is required for project managers to deal effectively with project change.