Large corporations have a significant amount of working capital tied into the acquisition and storage of spare parts. In the industry, spare parts inventory policies and strategies are often developed in isolation from reliability centered maintenance practices – this results in significant wasteful direct and indirect cost attached to spare parts management for the equipment operator. This report will focus on developing a methodology for minimizing lifecycle indirect and direct cost that comes from storing long lead time spares. A combined Monte-Carlo and Genetic Algorithm based optimization approach to finding the optimal spare parts storage strategy is proposed. In this study, the indirect and direct cost of having a spare part in the storage facility will be balanced against the cost of lost opportunity that results from decreased availability - a consequence of not having the required spare part available when an equipment failure event occurs. The results of this study present the benefits of optimizing long lead time spares through a joint Monte-Carlo & Genetic Algorithm based approach. / Engineering Management

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Poor input data quality used in repairable spare parts forecasting by aerospace small and midsize enterprises (SME) suppliers results in poor inventory practices that manifest into higher costs and critical supply shortage risks. Guided by the data quality management (DQM) theory as the conceptual framework, the purpose of this exploratory multiple case study was to identify the key strategies that the aerospace SME repairable spares suppliers use to maximize their input data quality used in forecasting repairable spare parts. The multiple case study comprised of a census sample of 6 forecasting business leaders from aerospace SME repairable spares suppliers located in the states of Florida and Kansas. The sample was collected via semistructured interviews and supporting documentation from the consenting participants and organizational websites. Eight core themes emanated from the application of the content data analysis process coupled with methodological triangulation. These themes were labeled as establish data governance, identify quality forecast input data sources, develop a sustainable relationship and collaboration with customers and vendors, utilize a strategic data quality system, conduct continuous input data quality analysis, identify input data quality measures, incorporate continuous improvement initiatives, and engage in data quality training and education. Of the 8 core themes, 6 aligned to the DQM theory's conceptual constructs while 2 surfaced as outliers. The key implication of the research toward positive social change may include the increased situational awareness for SME forecasting business leaders to focus on enhancing business practices for input data quality to forecast repairable spare parts to attain sustainable profits.

Risk based approaches are gaining currency as industry looks for rational, efficient and flexible approaches to managing their structures and equipment. When applied to inspection and maintenance of industrial assets, risk based approaches differ from other approaches mainly in their assessment of failure in its wider context and ramifications. These advanced techniques provide more insight into the causes and avoidance of structural failure and competing risks, as well as the resources needed to manage them. Measuring risk is a challenge that is being met with state of the art technology, skills, knowledge and experience. The thesis presents risk based approaches to solving two specific types of problem in the management of offshore structures and equipments. The first type is finding the optimum timing of an asset life management action such that financial benefit is maximised, considering the cost of the action and the risk (quantified in monetary terms) of not undertaking that action. The approach presented here is applied to managing remedial action in offshore wind farms and specifically to corroded wind turbine tower structures. The second type of problem is how to optimise resources using risk based criteria for managing competing demands. The approach presented here is applied to stocking spares in the shipping sector, where the cost of holding spares is balanced against the risk of failing to meet demands for spares. Risk is the leitmotiv running through this thesis. The approaches discussed here will find application in a variety of situations where competing risks are being managed within constraints.

[pt] O dimensionamento de equipamentos sobressalentes se mostra como importante ferramenta de análise de investimento para o projeto e planejamento da operação e manutenção de qualquer sistema de grande porte. Não sendo diferente no que contempla o sistema de distribuição elétrica no cenário brasileiro. Os sistemas de distribuição, regulados pela Agência Nacional de Energia Elétrica, precisam fornecer energia de forma segura, estável e com índices de defeito extremamente baixos, tornando-se cabíveis punições monetárias no caso de descumprimento das normas estabelecidas. Um dos pontos de maior sensibilidade em um sistema de distribuição são as subestações existentes no mesmo, onde os defeitos impactam um número elevado de consumidores, além de possuir equipamentos de grande custo de aquisição. A redundância em sistemas desse porte poderia reduzir consideravelmente as falhas, mas demandaria um investimento inicial muito elevado. Sendo assim, a existência de estoque estratégico torna-se relevante, visando diminuir a duração das falhas com o menor investimento possível. Os transformadores apresentam grande relevância em uma subestação, sendo possível a análise de estoque de unidades fixas, que atenderiam apenas uma localidade ou região, e o estoque de unidades móveis, que poderiam atender, ainda que em caráter provisório, diferentes regiões atingidas. Esta dissertação apresenta uma metodologia probabilística para a definição da estratégia de dimensionamento dos estoques de equipamentos reservas ao longo do tempo, dando enfoque às unidades móveis, sendo possível avaliar a confiabilidade do sistema, comparar os investimentos e custos operacionais de diferentes cenários. Permite também que sejam consideradas questões importantes, como o envelhecimento dos equipamentos, o aumento da carga com características diferentes para cada unidade a possibilidade de transferência de carga de uma unidade avariada para outra em funcionamento. Essas premissas proporcionam dados mais precisos para análise de investimentos, por considerar as condições individuais dos equipamentos. A ferramenta básica de análise será a simulação Monte Carlo cronológica, de modo a capturar precisamente todas as características do problema em questão. A metodologia acima proposta é aplicada a um grupo de transformadores da classe 138-13,8 kV, 25 MVA, visando demonstrar a capacidade da metodologia de encontrar as soluções condizentes do ponto de vista técnico e econômico. / [en] The sizing of equipment spares is an important investment analysis for the design and planning of the operation and maintenance of any large system. These concepts can also be applied to electric distribution systems of the interconnected Brazilian network. Distribution systems, regulated by the Brazilian Electricity Regulatory Agency, need to supply energy in a secure, stable, and extremely low fault rate, making monetary penalties possible in case of non-compliance with established standards. One of the most sensitive points in a distribution system is its current substations, where failures impact a large number of consumers, besides having relatively high-cost equipment. Redundancy in systems of this type could considerably reduce failures, but would require a very high initial investment. Thus, the need of a strategic inventory becomes relevant, aiming to reduce the duration of the failures with the least possible investment. Transformers are of great importance in an electric power station, whose spare requirements are usually assessed, but would only serve a locality or region, while the stock of mobile units, although on a temporary basis, would serve to different affected regions. This dissertation presents a probabilistic methodology for assessing of spare transformer requirements and the associated inventory acquisition strategy over time, focusing on mobile units. It includes the evaluation of reliability indices and comparison of investment and operational costs for different scenarios. It also allows important issues to be considered, such as equipment aging, load increasing with different characteristics for each unit, and the possibility of load transfers from one faulty unit to another in operation. These assumptions provide more accurate input data for investment analysis, considering the individual conditions of equipment. The basic tool to be used is the chronological Monte Carlo simulation that accurately captures all characteristics of the problem being solved. The proposed methodology is applied to a group of transformers of the class 138-13.8 kV, 25 MVA, aiming to demonstrate the ability of the proposed method to find the appropriate solutions from a technical and economic points of view.

The operation and maintenance phase of a complex technical system may deal with strategicdecisions for asset retirement and end-of-life management. When a fleet of aircraft reachesthe retirement phase, the operation of remaining fleet should still be kept at a defined level ofavailability. Obviously, the provisioning of spares is a key issue to support the maintenanceand operation of the remaining fleet. The best practice within the aviation industry is to re-usethe spares of retired aircraft to support the operational fleet. This is referred to parting-out.The purpose of the research conducted for this thesis has been to develop decision supportmethodologies, models and tools for the management of a sustainable part-out-based sparesprovisioning for an aircraft fleet during its retirement period. The proposed methodology willbe used to support the retirement process of aircraft fleet and enhance the organisation’scapability of making efficient and cost-effective decisions concerning the re-use of spare partsduring the retirement period. To achieve the purpose of this research, literature studies, casestudies, algorithm development and simulations have been conducted. Empirical data havebeen collected through document studies, interviews, and the perusal of archival records fromSaab Support and Services AB. The data analysis performed for this research has been basedon theories and methodologies within reliability analysis, cost modelling, spares forecasting,stock provisioning and decision making, in combination with the best practices implementedby the aviation industry for the end-of-life management and retirement of aircraft.In the present thesis, part-out-based spares provisioning (PBSP) program is proposed to utiliseretired aircraft units effectively as spare parts. The proposed approach is illustrated andverified through a case study performed on the “Saab-105” military aircraft fleet withinSwedish air force fleet. A PBSP programme is proposed, associated management activitiesare described, the key decision criteria are presented, and a functional framework for aneffective PBSP is suggested. The proposed PBSP program provides a foundation for furthermeasures and tasks to be performed within the retirement period, such as terminatingmaintenance contracts, discarding internal maintenance capabilities, reviewing stocks, scalingdown administrative processes (e.g. spares procurement and obsolescence monitoring), etc.An important part of the PBSP programme is the reliability analysis of multiple repairableunits, and this has been investigated, using parametric and non-parametric reliabilityapproaches. The aim is to identify a practical approach for estimation of the future sparedemand at fleet level. Furthermore, a set of computational models and search algorithm havebeen developed for the identification of applicable termination times, of both the parting-outprocess and the maintenance and repair actions performed on the units. This includestermination of the parting-out process (PO), the sending of parted-out units directly to storage(POS), and repair actions performed on the units received at the repair shops owing tocorrective (CM) and preventive (PM) maintenance, as well as the parted-out units that need tobe repaired (POM). The feasible termination alternatives are compared with regard to theirrespective costs and the most cost-effective solutions are identified.The results of the research study show that a PBSP programme can yield large reductions inmaintenance and spares procurement costs, while supporting operation of existing fleet athighest required availability. It also contributes positively to implement a green supply chainduring the retirement phase. The methodology and approaches introduced within the thesiscan be applied in other civil applications, such as energy, mining, process industry andtransportation sectors.

The research topic is: Tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. This research has specific reference to the SASOL Prillan plant based in SASOL, Sasolburg. The purpose of this research is to identify tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. These tools must be aimed to increase the proactive work capacity index, Figure 3, and to identify and/or develop tools that can be used by the engineering team of this explosives manufacturing plant to increase equipment reliability and performance. In this research assets include people. The meaning and application of asset management principles were researched and the tools needed to combine existing efforts and future needs are discussed. The human element to ensure the successful implementation of an asset management culture was researched and attributes of leaders and a change model is presented. This research was done into the wider engineering management discipline and not only maintenance. The method used to gather data was by means of interviews of a sample group within this organization. As this manufacturing unit makes use of subject matter experts, these support functions and plant personnel that were not interviewed, were issued with questionnaires to ensure that the sample group is a fair representation of the total manufacturing facility. To obtain a holistic view of potential shortcomings within the current maintenance strategy, all disciplines and levels within this operation were interviewed and commonalities of various asset management models were determined and used to define existing problem areas. This data was used to determine statistical correlations. The case study presented in Chapter 1 indicates that there is a case for change that can improve the proactive work capacity index of the engineering team. The results of this research confirm that there is in fact a real requirement to increase spares accuracy, improve on technical training as well as a need to establish visual performance indicators (dashboard) to measure overall equipment efficiency with the goal toTools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles increase equipment reliability and performance. The technical training referred to in this research reflects on training of people on equipment after investment in new technology. The current spares holding strategy is lacking equipment description accuracy. Furthermore, it is recommended that the implementation of career paths and development plans for individuals must be developed to create an environment of learning. The use of user status information captured on the computerized maintenance management system (SAP R/3) can add to the management of works orders and indicate where the focus must be to complete overdue work orders. Open work orders should be used to manage expenditure, to measure planning efficiency and to manage the cash flow of the business. The use of overall equipment efficiency and engineering efficiency measures is recommended and must be visually displayed on a “dashboard”. It was recommended that the engineering and operations personnel of this manufacturing plant be trained in asset management principles and that balanced scorecards are developed to ensure that the strategies of the various departments are aligned with the business strategy. Diagram 1 best illustrates the thinking and process flow of this research. The flow diagram shows five distinct stages and the appropriate objectives and/ or elements that were considered. The dissertation is also structured in this manner. All abbreviations, acronyms and definitions used in this document were listed in APPENDIX B / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

The research topic is: Tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. This research has specific reference to the SASOL Prillan plant based in SASOL, Sasolburg. The purpose of this research is to identify tools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles. These tools must be aimed to increase the proactive work capacity index, Figure 3, and to identify and/or develop tools that can be used by the engineering team of this explosives manufacturing plant to increase equipment reliability and performance. In this research assets include people. The meaning and application of asset management principles were researched and the tools needed to combine existing efforts and future needs are discussed. The human element to ensure the successful implementation of an asset management culture was researched and attributes of leaders and a change model is presented. This research was done into the wider engineering management discipline and not only maintenance. The method used to gather data was by means of interviews of a sample group within this organization. As this manufacturing unit makes use of subject matter experts, these support functions and plant personnel that were not interviewed, were issued with questionnaires to ensure that the sample group is a fair representation of the total manufacturing facility. To obtain a holistic view of potential shortcomings within the current maintenance strategy, all disciplines and levels within this operation were interviewed and commonalities of various asset management models were determined and used to define existing problem areas. This data was used to determine statistical correlations. The case study presented in Chapter 1 indicates that there is a case for change that can improve the proactive work capacity index of the engineering team. The results of this research confirm that there is in fact a real requirement to increase spares accuracy, improve on technical training as well as a need to establish visual performance indicators (dashboard) to measure overall equipment efficiency with the goal toTools for the revision of a maintenance strategy for an explosives manufacturing plant, using asset management principles increase equipment reliability and performance. The technical training referred to in this research reflects on training of people on equipment after investment in new technology. The current spares holding strategy is lacking equipment description accuracy. Furthermore, it is recommended that the implementation of career paths and development plans for individuals must be developed to create an environment of learning. The use of user status information captured on the computerized maintenance management system (SAP R/3) can add to the management of works orders and indicate where the focus must be to complete overdue work orders. Open work orders should be used to manage expenditure, to measure planning efficiency and to manage the cash flow of the business. The use of overall equipment efficiency and engineering efficiency measures is recommended and must be visually displayed on a “dashboard”. It was recommended that the engineering and operations personnel of this manufacturing plant be trained in asset management principles and that balanced scorecards are developed to ensure that the strategies of the various departments are aligned with the business strategy. Diagram 1 best illustrates the thinking and process flow of this research. The flow diagram shows five distinct stages and the appropriate objectives and/ or elements that were considered. The dissertation is also structured in this manner. All abbreviations, acronyms and definitions used in this document were listed in APPENDIX B / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

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