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Research Articles (Electrical Engineering)

Permanent URI for this collectionhttps://hdl.handle.net/10413/6858

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Browsing Research Articles (Electrical Engineering) by Author "Whitehead, Howard."

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    Application of maintenance tools and strategies in integrated risk management of critical physical assets.
    (Inderscience Publishers., 2011) Mkandawire, Burnet O'Brien.; Ijumba, Nelson Mutatina.; Whitehead, Howard.
    This paper critically analyses various tools, techniques and strategies; and proposes an ‘integrated risk management model’ that utilises advantages of the best combination of tools, techniques and strategies to manage risks thereby optimising operating costs whilst maximising returns on critical assets in high voltage networks; and physical assets in general. We used a triangulation method involving a longitudinal single case study within Malawian power sector, multiple (34) industrial case studies and sample surveys of selected Malawian and South African industries. It was shown that the electric power industry (70%) lacked a clear systemic maintenance and refurbishment risk management model due to the difficulty in determining optimum combination of tools. They also lacked technical skills needed to apply proactive strategies. The core value of tools is in planning of maintenance and refurbishment; and in contextualising, exploring, assessing, treating and monitoring of risks.
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    Asset management optimization through integrated systems thinking and N-1 contingency capability for refurbishment.
    (Institute of Electrical and Electronics Engineers., 2011-09) Ijumba, Nelson Mutatina.; Whitehead, Howard.; Mkandawire, Burnet O'Brien.
    This paper presents a systems view of refurbishment systems to evaluate root causes of suboptimal refurbishment. Case studies from ten selected South African and Malawian firms from largest electric power utilities, mining, petrochemical, and processing industries were used to establish causal relationships. Sample surveys of thirty four Malawian firms were used as part of a multimethod or triangulation approach to provide generalizations, validation and reliability. Of the surveyed firms, 66.7%, and of case studied firms 100%, showed that deferred refurbishment was a result of constrained capacity which led to components operating at higher loads, to lack of maintenance windows and to increased failure rates; there was no formal refurbishment model and technical skills base was the weakest asset management link. The study advances a novel way of depicting root causes of suboptimal refurbishment in typically complex dynamic structures using integrated systems thinking approach and applies analytical optimization tools, namely: Linear Programming (LP), metrics and N-1 contingency capability for refurbishment model for drilling deeper into causal typologies portrayed by systems thinking in order to solve optimization problems. A Total Refur-bishment Process model is advanced to replicate refurbishment decision structures for long term sustainability of industries as validated by industries studied.