Vibration covariate regression analysis of failure time data with the proportional hazards model

Please read the abstract in the section 00front of this documentDissertation (MEng (Mechanical Engineering))--University of Pretoria, 2006.Mechanical and Aeronautical Engineeringunrestricte

The possible influence of risk management, forecasting, and personnel training in physical asset management

CITATION: Schoeman, J. S. & Vlok, P. J. 2014. The possible influence of risk management, forecasting, and personnel training in physical asset management. South African Journal of Industrial Engineering, 25(2):96-104, doi:10.7166/25-2-740.The original publication is available at http://sajie.journals.ac.zaThe work presented in this paper highlights the possible effects of risk management, forecasting, and personnel training in the physical asset management environment. Each section is taken separately, and an argument is formed as to why it is important and what portion of the physical asset management five-year budget each should receive. This paper considers the long-term and short-term benefits in its conclusion that risk management should receive 60 per cent of the budget, personnel training 25 per cent, and forecasting the final 15 per cent.Hierdie studie beklemtoon die moontlike effekte wat risiko bestuur, voorspelling van voorvalle, en die opleiding van personeel kan hê binne die fisiese bate bestuur omgewing. Die afdelings word elk apart bespreek, en ’n argument word gevorm om te sê waarom die afdeling belangrik is en watter bedrag van ’n maatskappy se vyf- jaar begroting elk moet ontvang. Die finale besluit was dat risiko ’n totaal van 60 persent van die begroting moet ontvang omdat dit so ’n breë afdeling is, die opleiding van personeel vereis 25 persent, en die voorspelling van gebeure die laaste 15 persent.http://sajie.journals.ac.za/pub/article/view/740Publisher's versio

Advances in renewal decision-making utilising the proportional hazards model with vibration covariates

Increased competitiveness in the production world necessitates improved maintenance strategies to increase availabilities and drive down cost . The maintenance engineer is thus faced with the need to make more intelligent pre ventive renewal decisions . Two of the main techniques to achieve this is through Condition Monitoring (such as vibrat ion monitoring and oil anal ysis) and Statistical Failure Analysis (typically using probabilistic techniques) . The present paper discusses these techniques, their uses and weaknesses and then presents the Proportional Hazard Model as an solution to most of these weaknesses. It then goes on to compare the results of the different techniques in monetary terms, using a South African case study. This comparison shows clearly that the Proportional Hazards Model is superior to the present techniques and should be the preferred model for many actual maintenance situations.Verhoogde vlakke van mededinging in die produksie omgewing noodsaak verbeterde instandhouding strategies om beskikbaarheid van toerusting te verhoog en koste te minimeer. Instandhoudingsingenieurs moet gevolglik meer intellegente voorkomende hernuwings besluite neem. Twee prominente tegnieke om hierdie doelwit te bereik is Toestandsmonitering (soos vibrasie monitering of olie analise) en Statistiese Falingsanalise (gewoonlik m.b.v. probabilistiese metodes). In hierdie artikel beskou ons beide hierdie tegnieke, hulle gebruike en tekortkominge en stel dan die Proporsionele Gevaarkoers Model voor as 'n oplossing vir meeste van die tekortkominge. Die artikel vergelyk ook die verskillende tegnieke in geldelike terme deur gebruik te maak van 'n Suid-Afrikaanse gevalle studie. Hierdie vergelyking wys duidelik-uit dat die Proporsionele Gevaarkoers Model groter belofte inhou as die huidige tegnieke en dat dit die voorkeur oplossing behoort te wees in baie werklike instandhoudings situasies.http://sajie.journals.ac.z

Dynamic residual life estimation of industrial equipment based on failure intensity proportions

There is a world-wide drive to optimize maintenance decisions in an increasingly competitive manufacturing industry. Preventive maintenance if often the most organized and cost efficient strategy to follow, but a decision still has to be made on the optimal instant to perform preventive maintenance. Use based preventive maintenance decisions have been optimized through statistical analysis of failure date while predictive preventive maintenance (condition monitoring) has been optimized by utilizing more sophisticated technology. Very little work has however been done to combine the advantages of the two schools of thought. This thesis originated from a realization of the potential improvement in maintenance practice by combining use based preventive maintenance optimization techniques with high technology condition monitoring. In this thesis an approach is developed to estimate residual life of industrial equipment dynamically by combining statistical failure analysis and sophisticated condition monitoring technology. The approach is based on failure intensity proportions determined from historic survival time information and corresponding diagnostic information such as condition monitoring. Combined Proportional Intensity Models (PIMs) for non-repairable and repairable systems, containing the majority of conventional PIM enhancements as special cases, with numerical optimization techniques to solve for the regression coefficients, are derived. In addition to the residual life estimation approach, a user-friendly graphical method with which residual life estimates can be presented was also developed. This method is natural and easy to comprehend, even by inexperienced data analysts. The residual life estimation approach is applied to a typical data set from a South African industry and results are compared to those obtained from a similar, established maintenance decision support tool. This comparison showed that the approach developed in this thesis is relevant, practical and marginally better than the established decision support tool for certain criteria.Thesis (PhD (Industrial Engineering))--University of Pretoria, 2006.Industrial and Systems Engineeringunrestricte

Die terugbetalingsvermoë van die landbouprodusent as evalueringskriterium vir produksiekredietverskaffing

M.Com. (Business Management)Please refer to full text to view abstrac

A simplified numerical decision-making methodology for physical asset management decisions

CITATION: Burnett, S. & Vlok, P. J. 2014. A simplified numerical decision-making methodology for physical asset management decisions. South African Journal of Industrial Engineering, 25(1):162-175, doi:10.7166/25-1-689.The original publication is available at http://sajie.journals.ac.zaThe management of physical assets has become a popular field recently, and is acknowledged in many disciplines worldwide. Physical Asset Management (PAM) is a complex subject that requires the participation of many disciplines. Maintenance management, together with accurate and effective decision–making, is vital for achieving successful PAM. The primary objective of this research project was to identify the possibility of simplifying maintenance-related decision-making. With the focus on numerical decision-making techniques, the secondary objective was to investigate the practicality and useability of combining appropriate techniques to create an easily useable and understandable methodology to support maintenance-related decisions. The results confirm the practicality and useability of a simplified numerical decision-making methodology. By concentrating on the core operational questions related to maintenance, and by combining the most appropriate techniques, a simplified numerical decision-making methodology can ease the decision-making process on an operational level. This can accomplish successful PAM in a proactive, preventive and simplified manner.Die onderwerp van Fisiese Bate Bestuur (FBB) het ‘n gewilde navorsingsveld geraak oor die afgelope paar jaar. FBB is ‘n komplekse onderwerp en vereis insette van verskeie dissiplines. Effektiewe bestuur van instandhouding sowel as doeltreffende besluitneming is noodsaaklik vir suksesvolle FBB. Die primêre doel van hierdie navorsingsprojek was om die moontlikheid van vereenvoudigde besluitneming met betrekking tot instandhouding, te ondersoek. Met die fokus op numeriese besluitnemingstegnieke was die sekondêre doel om die praktiese toepassing van ‘n gepaste tegniek-kombinasie te ondersoek om uiteindelik ‘n maklike, bruikbare en verstaanbare tegniek-kombinasie te skep wat instandhouding verwante besluite kan ondersteun. Die resultate bevestig die bruikbaarheid van ‘n eenvoudige numeriese besluitnemings tegniek-kombinasie om die besluitnemingsproses op operasionele vlak te verlig. Deur te konsentreer op instandhouding verwante kern operasionele vrae, en deur die mees gepaste tegnieke te kombineer, kan ‘n vereenvoudige numeriese besluitnemingsmetodologie die besluitnemingsproses op operasionele vlak verlig. Dit kan FBB suksesvol op ‘n pro-aktiewe, voorkomende en vereenvoudige manier uitvoer.http://sajie.journals.ac.za/pub/article/view/689Publisher's versio

Supply chain management : a framework of understanding

CITATION: Du Toit, D. & Vlok, P. J. 2014. Supply chain management: a framework of understanding. South African Journal of Industrial Engineering, 25(3):25-38, doi:10.7166/25-3-743.The original publication is available at http://sajie.journals.ac.zaThe topic of supply chain management (SCM) is complex to understand because it encompasses many different flows of activities, components, functions, and role-players. The literature is scattered across multiple functions, varies in scope, and is often confined to certain elements within SCM. This article aims to provide a literature overview of SCM. It is explained with the aid of a newly-developed framework of understanding that offers a graphical representation of the term. It unifies and condenses different components within SCM and shows the relationship between them. The framework was developed by identifying the main themes in the definitions for SCM, examining existing categorisations and frameworks in SCM, and analysing frameworks in other disciplines. The outcome of this article can be used as a guide to explain and orientate researchers and practitioners in the field.Die onderwerp van voorsieningskettingbestuur (VKB) is kompleks om te verstaan omdat dit baie verskillende komponente, vloei van aktiwiteite, funksies, en rolspelers insluit. Die literatuur oor VKB is versprei oor verskeie funksies, wissel in omvang, en word dikwels beperk tot sekere elemente binne VKB. Die doel van hierdie artikel is om ’n literatuur oorsig oor die onderwerp van VKB te voorsien. VKB word verduidelik met behulp van ’n nuut-ontwikkelde raamwerk van verstaan: ’n grafiese voorstelling van die term. Dit verenig die verskillende komponente binne VKB, en toon die verwantskap tussen hulle. Die raamwerk is ontwikkel deur die belangrikste temas in die definisies van VKB te bestudeer, en bestaande kategorisering en verwysingsmodelle te ontleed. Die uitkomste van die artikel kan gebruik word as ’n gids om navorsers en praktisyne te oriënteer in die veld.http://sajie.journals.ac.za/pub/article/view/743Publisher's versio

Application of the Aviation Derived Maintenance Free Operating Period Concept in the South African Mining Industry

This paper analyses the use and possible application of the concept of the maintenance free operating period (MFOP), derived from the aviation sector, in the mining industry. The traditionally used reliability requirement, mean time between failure (MTBF), has been found to have several inherent problems with its application and definition. These problems are explained in this paper. It also provides a brief overview of the field of physical asset management (PAM), the overall domain of the research, and thereafter provides a characterisation of MTBF and its current use in the mining industry. MFOP is then introduced and contrasted with MTBF. A methodology for the analysis of MFOP performance is introduced and then applied to a case study conducted at an Anglo American platinum mine

ADVANCES IN RENEWAL DECISION-MAKING UTILISING THE PROPORTIONAL HAZARDS MODEL WITH VIBRATION COVARIATES

<p>ENGLISH ABSTRACT: Increased competitiveness in the production world necessitates improved maintenance strategies to increase availabilities and drive down cost . The maintenance engineer is thus faced with the need to make more intelligent pre ventive renewal decisions . Two of the main techniques to achieve this is through Condition Monitoring (such as vibrat ion monitoring and oil anal ysis) and Statistical Failure Analysis (typically using probabilistic techniques) . The present paper discusses these techniques, their uses and weaknesses and then presents th e Proportional Hazard Model as an solution to most of these weaknesses. It then goes on to compare the results of the different techniques in monetary terms, using a South African case study. This comparison shows clearly that the Proportional Hazards Model is sup erior to the present t echniques and should be the preferred model for many actual maintenance situations.</p><p>AFRIKAANSE OPSOMMING: Verhoogde vlakke van mededinging in die produksie omgewing noodsaak verbeterde instandhouding strategies om beskikbaarheid van toerusting te verhoog en koste te minimeer. Instandhoudingsingenieurs moet gevolglik meer intellegente voorkomende hernuwings besluite neem. Twee prominente tegnieke om hierdie doelwit te bereik is Toestandsmonitering (soos vibrasie monitering of olie analise) en Statistiese Falingsanalise (gewoonlik m.b.v. probabilistiese metodes). In hierdie artikel beskou ons beide hierdie tegnieke, hulle gebruike en tekortkominge en stel dan die Proporsionele Gevaarkoers Model voor as 'n oplossing vir meeste van die tekortkominge. Die artikel vergelyk ook die verskillende tegnieke in geldelike terme deur gebruik te maak van 'n Suid-Afrikaanse gevalle studie. Hierdie vergelyking wys duidelik-uit dat die Proporsionele Gevaarkoers Model groter beloft e inhou as die huidige tegni eke en dat dit die voorkeur oplossing behoort te wees in baie werklike instandhoudings situasies.</p&gt

Optimising investment in asset management using the multivariate asset management assessment topography

CITATION: Bam, W. G. & Vlok, P. J. 2014. Optimising investment in asset management using the multivariate asset management assessment topography. South African Journal of Industrial Engineering, 25(2):29-38, doi:10.7166/25-2-705.The original publication is available at http://sajie.journals.ac.zaThe multivariate asset management assessment topography (MAMAT) was developed to quantify, and represent graphically, development, adoption, and performance of a business’ asset management (AM) systems, as described by standards such as PAS 55. The MAMAT provides a way to visualise clearly the strengths and weaknesses of a business’ asset management system. Building on MAMAT, a model describing the relationship between the commitment of resources and the corresponding improvement in the MAMAT assessment outcome is proposed. The goal is to develop an optimisation model that will maximise financial benefits by improving the MAMAT assessment score achieved by a business, while minimising the investment required to attain this improvement. This is achieved by determining the optimal allocation of resources to the different subcategories of the MAMAT assessment framework. The multi-objective cross-entropy method (MOO CEM) is used to find the Pareto set of solutions for this problem. In order to showcase the intended industry application and use of the optimisation model, a hypothetical case study is executed and described in this paper. From this application, it was found that the MOO CEM finds useful solutions that can support the implementation of standards such as PAS 55 by prioritising and assigning resources to implementation activities.Die meerveranderlike batebestuur evalueringstopografie (MBE) is ontwikkel om ’n besigheid se prestasie te kwantifiseer en grafies voor te stel. Dit word gedoen aan die hand van ’n volwassenheid-, gebruiklikheids- en prestasie indeks van die batebestuur stelsel soos beskryf deur internasionale standaarde soos PAS 55. Die MBE bied ’n manier om duidelik die sterk- en swakpunte van ’n besigheid te visualiseer en te identifiseer met betrekking tot die batebestuur stelsel. Gebaseer op die MBE word ’n model voorgestel wat die verhouding tussen die gebruik van hulpbronne en die ooreenstemmende verbetering in die MBE assesseringsuitkomste beskryf. Die fokus van hierdie studie is om ’n optimeringsmodel te ontwikkel wat die finansiële voordele van die verbetering van die MBE assesseringstellings maksimeer, terwyl dit die finansiële belegging wat benodig word om dit teweeg te bring minimeer. Dit word gedoen deur die bepaling van die optimale toewysing van hulpbronne aan die verskillende onderafdelings van die MBE assesseringsraamwerk. Die veeldoelige kruis-entropie metode (VD KEM) word gebruik om die Pareto stel van oplossings vir hierdie probleem te vind. Ten einde die voorgenome nywerheidstoepassing ten toon te stel, is ’n hipotetiese gevallestudie uitgevoer en beskryf in hierdie artikel. Vanuit hierdie aanwending is bevind dat die MD KEM nuttige oplossings vind wat die implementering van standaarde soos PAS 55 ondersteun deur die prioritisering en toewysing van hulpbronne aan implementeringsaktiwiteite.http://sajie.journals.ac.za/pub/article/view/705Publisher's versio