Scielo RSS <![CDATA[South African Journal of Industrial Engineering]]> http://www.scielo.org.za/rss.php?pid=2224-789020140002&lang=en vol. 25 num. 2 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za <![CDATA[<b>Note from the editor</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200001&lng=en&nrm=iso&tlng=en <![CDATA[<b>Improvements in the capability profile of 3-D printing: An update</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200002&lng=en&nrm=iso&tlng=en Knowledge about the capabilities of a production system is an important issue. The three-dimensional (3-D) printing (drop-on-bed) process has become a well-established Additive Manufacturing (AM) technology. Initially intended for use mainly as a concept modeller, its scope of application has expanded to include, among others, fit and functional models, pattern-making for casting and moulding processes, rapid tooling, and medical and architectural models. This growth in applications has stimulated a reciprocal improvement in available materials and the technological capabilities of 3-D printing, such as accuracy, strength and elongation, surface finish, build time, and cost. These factors are of significance to users who want to control their processes better and to designers who want to define their expectations and determine their requirements. Thus this paper aims to provide a technical update, highlighting the influence level of different factors on a system's capabilities. This paper uses the example of the ZPrinter 310 system from the Z Corporation, applies appropriate statistical techniques, and takes into consideration the latest material and machine developments, in order to report on the current improvements of the capability profile of this important process.<hr/>Kennis oor die vermoëns van 'n produksie sisteem is 'n baie belangrike kwessie. Die 3-D druk proses het 'n goed gevestigde additiewe vervaardigingstegnologie geraak. Aanvanklik was die hoof doel hiervan om konsepte te modelleer, maar nou is die toepassing uitgebrei om, onder andere, pas en funksionele modelle, patroon vervaardiging van giet prosesse, snel vervaardiging van gereedskap, mediese modelle, en argitektoniese modelle in te sluit. Hierdie groei in aantal toepassings het 'n wedersydse verbetering in die beskikbaarheid so wel as tegnologiese vermoëns van 3-D druk soos akkuraatheid, sterkte, verlenging, afwerking, bou tyd, en kostes tot gevolg gehad. Hierdie faktore is baie belangrik vir gebruikers om beter beheer toe te pas oor hul prosesse, en vir ontwerpers om hul verwagtinge te definieer en om vereistes te bepaal. Hierdie artikel het ten doel om 'n tegniese opdatering te gee van wat die invloed van verskillende faktore op 'n sisteem se vermoëns is. Deur gebruik te maak van die ZPrinter 310 sisteem van Z-Corporation as voorbeeld, en met die toepassing van gepaste statistiese tegnieke en inagneming van onlangse materiaal- en masjienontwikkelinge, word die nuutste verbeteringe van die vermoënsprofiel vir 3-D druk tegnologie bespreek. <![CDATA[<b>An empirical study on the critical success factors of small- to medium-sized projects in a South African mining company</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200003&lng=en&nrm=iso&tlng=en Projects that fail, for whatever reason, can impact negatively on society, organisations, and other stakeholders. A number of researchers have identified various critical success factors (CSFs) that can influence the outcome and success of a project. This research therefore aims to determine the CSFs that influence various success measures of small- to medium-sized projects at a South African mining company, Exxaro Resources' Grootegeluk Coal Mine. Other objectives of this research include determining the extent of the impacts of these CSFs on the different success measures of a project. The investigation suggests that there are correlations among CSFs, and that certain factors impact the outcome of projects far more than others. This research finds that the single most important CSF for small- to medium-sized projects is the selection of a competent project manager. The competent project manager is characterised by a group of interrelated CSF factors: good leadership, commitment, and learning from past experiences. Based on the research results, other CSFs are discussed and explored in order for recommendations to be made on how this mining company, and possibly other organisations, can achieve greater project success.<hr/>Mislukte projekte kan negatiewe impakte op die samelewing, organisasies en ander belanghebbendes hê. In die literatuur is daar reeds verskeie kritiese suksesfaktore geïdentifiseer wat die uitkoms en sukses van 'n projek kan beïnvloed. Hierdie navorsing mik daarna om die kritiese suksesfaktore wat verskeie suksesmaatstawwe van klein- tot mediumgrootte projekte by Exxaro Resources se Grootgeluk steenkoolmyn in Suid-Afrika beïnvloed. Nog 'n doelstellings van die studie sluit in die bepaal van die mate van die impak van hierdie kritiese suksesfaktore op die verskillende suksesmaatstawwe van 'n projek. Die ondersoek dui daarop dat daar korrelasies onder kritiese suksesfaktore bestaan en dat sekere faktore 'n baie groter invloed op die uitkoms van projekte het as ander. Die belangrikste kritiese suksesfaktor vir klein- tot mediumgrootte projekte is die aanstel van 'n bevoegde projekbestuurder. 'n Bevoegde projekbestuurder word gekenmerk deur etlike onderlinge kritiese suksesfaktore, naamlik goeie leierseienskappe, toewyding en ervaring. Ander kritiese suksesfaktore word op grond van hierdie studie bespreek en ondersoek om aanbevelings te maak oor hoe die mynboumaatskappy, en moontlik ander organisasies, verbeterde projek sukses kan behaal. <![CDATA[<b>Optimising invesment in asset management using the multivariate asset management assessment topography</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200004&lng=en&nrm=iso&tlng=en The 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.<hr/>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. <![CDATA[<b>Development of a Stereolithography (STL) input and Computer Numerical Control (CNC) output algorithm for an entry-level 3-D printer</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200005&lng=en&nrm=iso&tlng=en This paper presents a prototype Stereolithography (STL) file format slicing and tool-path generation algorithm, which serves as a data front-end for a Rapid Prototyping (RP) entry-level three-dimensional (3-D) printer. Used mainly in Additive Manufacturing (AM), 3-D printers are devices that apply plastic, ceramic, and metal, layer by layer, in all three dimensions on a flat surface (X, Y, and Z axis). 3-D printers, unfortunately, cannot print an object without a special algorithm that is required to create the Computer Numerical Control (CNC) instructions for printing. An STL algorithm therefore forms a critical component for Layered Manufacturing (LM), also referred to as RP. The purpose of this study was to develop an algorithm that is capable of processing and slicing an STL file or multiple files, resulting in a tool-path, and finally compiling a CNC file for an entry-level 3D printer. The prototype algorithm was implemented for an entry-level 3-D printer that utilises the Fused Deposition Modelling (FDM) process or Solid Freeform Fabrication (SFF) process; an AM technology. Following an experimental method, the full data flow path for the prototype algorithm was developed, starting with STL data files, and then processing the STL data file into a G-code file format by slicing the model and creating a tool-path. This layering method is used by most 3-D printers to turn a 2-D object into a 3-D object. The STL algorithm developed in this study presents innovative opportunities for LM, since it allows engineers and architects to transform their ideas easily into a solid model in a fast, simple, and cheap way. This is accomplished by allowing STL models to be sliced rapidly, effectively, and without error, and finally to be processed and prepared into a G-code print file.<hr/>'n Prototipe stereolitografie (STL) dokument ontvou en instrumenttrajek generasie algoritme vir 'n intreevlak driedimensionele drukker word in dié studie bekendgestel. Driedimensionele drukkers word hoofsaaklik in toevoegingsvervaardiging gebruik deur lae plastiek, keramiek of metaal in al drie rigtings (x, y en z) op 'n plat oppervlak te deponeer. Rekenaar numeriese beheer word egter benodig om die driedimensionele drukker te begelei. Die STL algoritme vorm dus 'n integrale deel vir laag-op-laag vervaardiging. Die doel van hierdie studie is om 'n algoritme te ontwikkel wat die vermoë het om een of meer STL dokumente te prosesseer en te ontvou en 'n gepaste instrumenttrajek te formuleer en daaruit beheerinstruksies vir die drukker te genereer. Die STL lêer is geprosesseer tot 'n G-kode lêer deur middel van die algoritme. Die ontwikkelde algoritme hou innoverende geleenthede in vir laag-op-laag vervaardiging, aangesien dit aan ingenieurs en argitekte toelaat om vinnig en maklik hul idees in driedimensionele soliede voorwerpe te omskep. Dit is moontlik deur die STL modelle vinnig en sonder foute te ontvou en te prosesseer tot 'n G-kode beheerlêer. <![CDATA[<b>A frameworks for structural modelling of an RFID-enabled intelligent distributed manufacturing control system</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200006&lng=en&nrm=iso&tlng=en A modern manufacturing facility typically contains several distributed control systems, such as machining stations, assembly stations, and material handling and storage systems. Integrating Radio Frequency Identification (RFID) technology into these control systems provides a basis for monitoring and configuring their components in real-time. With the right structural modelling, it is then possible to evaluate designs and translate them into new operational applications almost immediately. This paper proposes an architecture for the structural modelling of an intelligent distributed control system for a manufacturing facility, by utilising RFID technology. Emphasis is placed on a requirements analysis of the manufacturing system, the design of RFID-enabled intelligent distributed control systems using Unified Modelling Language (UML) diagrams, and the use of efficient algorithms and tools for the implementation of these systems.<hr/>'n Moderne vervaardigingsaanleg bestaan gewoonlik uit verskeie verspreide beheerstelsels soos masjineringstasies, monteerstasies en materiaalhantering- en stoorstelsels. Deur Radio Frekwensie Identifikasie (RFID) tegnologie met hierdie beheerstelsels te integreer, verskaf 'n basis vir intydse monitor en instel van die beheerstelsels se komponente. Met die regte strukturele modelleringbenadering is dit moontlik om ontwerpe byna onmiddellik te evalueer en verwerk tot nuwe operasionele toepassings. Hierdie navorsing stel 'n argitektuur voor vir die strukturele modellering van 'n intelligente verspreide beheerstelsel vir 'n vervaardigingsaanleg deur middel van RFID tegnologie. Die klem word op 'n behoefte-analise van die vervaardigingstelsel, die ontwerp van die RFID intelligente verspreide beheerstelsels deur UML diagramme en die gebruik van effektiewe algoritmes en gereedskap vir die implementering van die stelsels, geplaas. <![CDATA[<b>Additive manufacturing as an enabler for enhanced consumer involvement</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200007&lng=en&nrm=iso&tlng=en This paper draws on previous work by the authors that aimed to use functional prototypes, produced using additive manufacturing (AM), as a means to draw customer input and preferences into the development of new products. This technique is referred to as Customer Interaction through Functional Prototypes (CIFP). The CIFP philosophy has been proven in both consumer and medical products. In recent years, the authors have developed further concepts of AM-enabled enhanced consumer involvement within their respective research teams. This paper discusses the extended use of CIFP to develop innovative new product concepts in the Vaal University of Technology, to support grant-holders of the Industrial Development's Corporation (IDC) Support Programme for Industrial Innovation (SPII) and the Technology and Innovation Agency (TIA). The paper goes on to discuss a novel method of consumer interaction developed at Loughborough University, referred to as a Computer-aided Consumer Design (CaCODE). This technique allows non-designers to take an existing product design (e.g., a pen) and modify its shape in real time, in order to create a customised version of the product that meets their needs. The modification is limited within pre-defined parameters to make sure that any final design is functional and can be produced using AM.<hr/>Hierdie artikel is geskoei op die gebruik van toevoegingsvervaardiging om kliënt insette en voorkeure in te sluit by die ontwikkeling van nuwe produkte. Die tegniek word die Kliënt Interaksie deur Funksionele Prototipes (CIFP) genoem. Die CIFP filosofie is al bewys in verbruikers- en mediese produkte. Verdere konsepte vir die gebruik van toevoegingsvervaardiging om kliënt betrokkenheid te bevorder is die die outeurs ontwikkel. Hierdie artikel bespreek die uitgebreide gebruik van CIFP om innoverende nuwe produkte te ontwikkel by die Vaal Universiteit van Tegnologie ter ondersteuning van navorsers wat steun van die Industriële Ontwikellings Korporasie (IDC) en die Tegnologie en Innovasie Agentskap (TIA) ontvang. Die artikel bespreek verder 'n nuwe metode vir verbruiker interaksie soos ontwikkel by Loughborough Universiteit, bekend as Rekenaar gesteunde Verbruiker Ontwerp (CaCode). Dié tegniek laat ontwerp-leke toe om 'n bestaande produk aan te pas om aan hulle vereistes te voldoen. Hierdie aanpassing is beperk binne voorafbepaalde parameters om te verseker dat die finale ontwerp funksioneel en vervaardigbaar is. <![CDATA[<b>Quantifying Quality Management System performance in order to improve business performance</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200008&lng=en&nrm=iso&tlng=en This study investigates current methods of measuring quality management system (QMS) performance. It introduces a methodology to quantify QMS performance in order to provide a reference point for improved QMS performance and, in turn, the business's performance. By introducing metadata into historical or current QMS internal audit data, the study shows that it is possible, over time, to extract various levels of value-adding data, ranging from high-level, strategic, direction-oriented insight, to process effectiveness and implementation-level guidance. This is accomplished by a repeatable process of infusing cause and effect theming data and process-consequence severity data into the QMS audit-findings data, and subsequently analysing the additional metadata.<hr/>Die huidige metodes om gehaltebestuurstelsels se prestasie te beoordeel word ondersoek. 'n Metode om gehaltebestuurstelsels se prestasie te kwantifiseer word bekendgestel om as 'n verwysing vir verbeterde gehaltebestuurstelsels op te tree. Die studie toon dat, deur metadata in historiese of huidige gehaltebestuurstelsels se interne oudit data in te voer, dit moontlik is om, met die verloop van tyd, waardevolle data te onttrek. Hierdie data strek van hoë vlak, strategiese, rigting-georiënteerde insig tot proses doeltreffendheid en implementasievlak leiding. Dit is vermag deur 'n herhaalbare proses van oorsaak-en-gevolg data en prosesgevolg data in die gehaltebestuurstelsel in te voer en gevolglik die addisionele metadata te analiseer. <![CDATA[<b>The possible influence of risk management, forecasting, and personnel training in physical asset management</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200009&lng=en&nrm=iso&tlng=en The 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.<hr/>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. <![CDATA[<b>Managing uncertainty in typical mining project studies</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200010&lng=en&nrm=iso&tlng=en Mining project studies and their evaluation are characterised by high uncertainties. These uncertainties range in magnitude from, and are prevalent in, the geological data on which the project is based, through to the final prices received for the ore, metal, or mineral being sold to the market. The process for managing uncertainties in mining projects could have a huge impact on the decision about the final option and on the project composition. It is therefore critical that a systematic process is followed that manages these uncertainties effectively and consistently throughout the project phases, and when evaluating various options one against the other. This paper discusses the results of an investigation to determine the extent to which risk management was applied in twenty different project studies in the mining environment. The results of these studies indicate that uncertainties relating to typical mining project studies are not well understood or managed. A process to manage these uncertainties throughout the project development phases was developed and used in a typical pre-feasibility study. The results indicate that the process can be successfully implemented; and that the process helps to develop the project faster by focusing the project teams most on the uncertainties that affect the project need or requirement.<hr/>Projekstudies in die mynboubedryf en die evaluasie van sodanige projekte word gekenmerk deur hoë onsekerheid. Hierdie onsekerhede wissel in grootte, en is teenwoordig vanaf die geologiese data waarop die projek gebaseer is tot by die finale prys waarvoor die erts, metaal, of mineraal verkoop kan word. Die proses wat gebruik word om die onsekerhede in mynbouprojekte te bestuur kan 'n groot impak hê op die uiteindelike opsie wat gekies word en die samestelling van die projek. Dit is derhalwe van uiterste belang dat 'n sistematiese proses gevolg word om die onsekerhede effektief te bestuur deur die verloop van die projekfases en wanneer alternatiewe met mekaar vergelyk word. Hierdie artikel bespreek die resultate van 'n ondersoek wat gedoen is om te bepaal tot watter mate risikobestuur toegepas is vir twintig projekstudies in die mynbou-omgewing. Die resultate van hierdie navorsingsprojek in die mynboubedryf het aangetoon dat die onsekerhede met betrekking tot tipiese projekstudies in mynbou nie goed verstaan word deur bestuur nie. 'n Proses om hierdie onsekerhede deur die loop van die ontwikkelingsfases van die projek te bestuur is ontwikkel en toegepas op 'n tipiese voor-doenlikheidstudie. Die resultate toon aan dat die proses suksesvol geïmplementeer kan word en dat die projek vinniger ontwikkel kan word deur die projekspanne te fokus op die onsekerhede wat die behoefte van die projek die meeste beïnvloed. <![CDATA[<b>A survey of the practices of the approaches taught in an Industrial Engineering undergraduate programme</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200011&lng=en&nrm=iso&tlng=en The Saudi labour market has recently witnessed intense competition between locally-graduated Industrial Engineers and those graduating from international universities. This has compelled local IE departments to find ways to improve the quality of their educational programmes and to ensure their alignment with the labour market's needs. To this end, insightful information can be obtained by contacting alumni and soliciting their perceptions of their education. However, empirical investigations based on this approach are rarely reported in the literature. To fill this gap, this study reports the results of a survey that was conducted to examine the gap between what is practised and what is taught in the Industrial Engineering (IE) programme at King Abdulaziz University (KAU). Apart from discussing the main characteristics of the alumni's employers, the study revealed that 'Engineering Economy' involves the most applied techniques in practice, whereas 'Engineering Management' incorporates the most applicable approaches. The limited use of IE techniques was mainly attributed to poor cooperation between practitioners and academics, and the simplistic nature of the problems addressed in the university curriculum compared with complex real-life ones. To deal with some of the identified problems, this paper argues for advisory board members to engage with industry when designing the curriculum, and for the adoption of problem-based learning.<hr/>Die Saoedi arbeidsmark ervaar deesdae intense kompetisie tussen plaaslike gegradueerde bedryfsingenieurs en bedryfsingenieurs van buitelandse universiteite. Dit het die plaaslike bedryfsingenieurswese departemente gedwing om van hul akademiese programme se standaarde te verbeter. Insiggewende inligting kan ingewin word deur alumni te kontak en na hul persepsies oor hulle akademiese opvoeding te vra. Empiriese ondersoeke op hierdie benadering gegrond word egter selde gepubliseer. Hierdie studie doen egter verslag oor die resultate van 'n peiling, wat bedoel is om die verskil tussen dit wat toegepas word in die industrie en dit wat onderrig word by die Koning Abdulaziz Universiteit, te bepaal. Die studie bespreek nie net die hoofeienskappe van die alumni se werkgewers nie, maar toon ook dat ingenieursekonomie die mees toegepaste tegnieke behels, terwyl ingenieursbestuur die mees toegepaste benaderings behels. Die beperkte gebruik van bedryfsingenieurswese tegnieke word hoofsaaklik toegeskryf aan swak samewerking van akademici en praktisyns en die eenvoudige aard van die probleme op universiteit aangeraak teenoor die ingewikkelde probleme in die industrie. Om sekere van hierdie geïdentifiseerde probleme aan te spreek word die adviesraadslede aangemoedig om meer in oorleg met die industrie die kurrikulum te ontwerp en om 'n probleem georiënteerde leerplan aan te neem. <![CDATA[<b>Nintendo Wii remotes provide a reconfigurable tool-changing unit with an automatic calibration capability</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200012&lng=en&nrm=iso&tlng=en Modular machines within the reconfigurable manufacturing paradigm require auxiliary modules to enhance the system's capability. A tool-changing unit was developed as one of these auxiliary modules. The unit had to be able to adapt itself efficiently to changes in the configuration of the machine it was servicing. This necessitated the development of a realtime 3D tracking system in order for the unit to sense alterations in the position of the spindle to which it was delivering tools. An economic positioning system was produced using Nintendo Wii remotes. This paper presents the development, implementation, and testing of this positioning system.<hr/>Modulêre masjiene binne die herkonfigureerbare vervaardigingsparadigma vereis addisionele modules om die stelsel se vermoë te verbeter. 'n Gereedskapveranderingseenheid is ontwikkel as een van hierdie modules. Die eenheid moet in staat wees om doeltreffend aan te pas tot veranderinge in die konfigurasie van die masjien. Dit het gelei tot die ontwikkeling van 'n intydse driedimensionele opsporingstelsel sodat die module veranderinge in die posisie van die spil kan bepaal. 'n Ekonomiese posisioneringstelsel is ontwikkel deur die gebruik van Nintendo Wii afstandbeheer kontroles. Hierdie artikel bespreek die ontwikkeling, implementering en toets van die posisioneringstelsel. <![CDATA[<b>Development of an eco-efficient product/process for the vulcanising industry</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200013&lng=en&nrm=iso&tlng=en This paper presents the development of an eco-efficient product/process, which has improved mechanical properties from the introduction of natural fibres in the EPDM (Ethylene-Propylene-Diene-Terpolymer) rubber formulation. The optimisation analysis is made by a fractional factorial design 2(11-7). Different formulations were evaluated using a multi-response desirability function, with the aim of finding efficient levels for the manufacturing time-cycle, improving the mechanical properties of the product, and reducing the raw material costs. The development of an eco-efficient product/process generates a sustainable alternative to conventional manufacturing.<hr/>Die ontwikkeling van 'n omgewingsdoeltreffende produk of proses, wat verbeterde meganiese eienskappe het as gevolg van die toevoeging van natuurlike vesels in die EPDM ('n tipe polimeer) rubber formulering word voorgehou. Die optimiseringsanalise is gedoen deur 'n breukdeel faktoriaal ontwerp 2(11-7). Verskillende formulerings is geëvalueer deur 'n multi-reaksie wenslikheidsfunksie met die doel om doeltreffende vlakke vir die vervaardigingstydsiklus te vind en sodoende die meganiese eienskappe van die produk te verbeter en die roumateriaalkoste te verminder. Die ontwikkeling van 'n omgewingsdoeltreffende produk of proses genereer 'n volhoubare alternatief tot konvensionele vervaardiging. of Robotic Engineering, UPG. <![CDATA[<b>A strategic frameworrk to utilise venture capital funding to develop manufacturing SMEs in South Africa</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200014&lng=en&nrm=iso&tlng=en SMEs contribute considerably to the national GDP and to private sector employment, but they struggle to gain access to the funding needed to support business sustainability and growth. Venture capital provides the necessary funding, but SMEs lack understanding of the business value curve utilised by financiers to gauge the risk-reward characteristics of an investment. Strategies need to convey how the business model will evolve in order to deliver on the strategic intent. A framework is proposed through which SMEs can develop a strategy aligned with investor requirements. As a case study, the framework is applied to the local tooling sector.<hr/>SMEs dra betekenisvol by tot die nasionale BBP en werkskepping in die private sektor, maar SMEs sukkel om toegang te kry tot befondsing wat nodig is vir groei en volhoubaarheid. Waagkapitaal kan die nodige befondsing verskaf, maar SMEs benodig kennis van die besigheidswaarde kurwe, wat deur beleggers gebruik word om die risiko-opbrengs van 'n belegging te assesseer. Strategieë moet oordra hoe die besigheidsmodel die strategiese intensie gaan aflewer. 'n Raamwerk word voorgestel waardeur die SME 'n strategie kan ontwikkel wat belyn is met die vereistes van beleggers. As gevallestudie word die raamwerk toegepas op die plaaslike gereedskap sektor. <![CDATA[<b>Functional components produced by multi-jet modelling combined with electroforming and machining</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200015&lng=en&nrm=iso&tlng=en In fuel cell technology, certain components are used that are responsible for guiding liquid media. When these components are produced by conventional manufacturing, there are often sealing issues, and trouble- and maintenance-free deployment cannot be ensured. Against this background, a new process combination has been developed in a joint project between the University of Duisburg-Essen, the Center for Fuel Cell Technology (ZBT), and the company Galvano-T electroplating forming GmbH. The approach is to combine multi-jet modelling (MJM), electroforming and milling in order to produce a defined external geometry. The wax models are generated on copper base plates and copper-coated to a desirable thickness. Following this, the undefined electroplated surfaces are machined to achieve the desired measurement, and the wax is melted out. This paper presents, first, how this process is technically feasible, then describes how the MJM on a 3-D Systems ThermoJet was adapted to stabilise the process.In the AiF-sponsored ZIM project, existing limits and possibilities are shown and different approaches of electroplating are investigated. This paper explores whether or not activation of the wax structure by a conductive initial layer is required. Using the described process chain, different parts were built: a heat exchanger, a vaporiser, and a reformer (in which pellets were integrated in an intermediate step). In addition, multiple-layer parts with different functions were built by repeating the process combination several times.<hr/>Sekere komponente in brandstofsel tegnologie is nodig vir die lei van vloeistowwe. Daar is dikwels seël probleme wanneer hierdie komponente met konvensionele metodes vervaardig word en probleem- en instandhoudingsvrye ontplooiing kan nie gewaarborg word nie. 'n Nuwe proses kombinasie is ontwikkel in 'n gesamentlike projek tussen die Universiteit van Duisburg-Essen se Sentrum vir Brandstofsel Tegnologie en Galvano-T GmbH, 'n vervaardiger wat van elektrovorming gebruik maak. Die benadering is om multi-straalmodellering te kombineer met elektrovorming en freeswerk om 'n eksterne geometrie te produseer. Die waksmodelle word gegenereer op koper basis plate en word met koper bedek tot op die verlangde dikte. Gevolglik word die elektroplateerde oppervlakke gemasjineer tot op die verlangde afmetings en die waks word weggesmelt. Hierdie artikel beskryf hoe dié proses tegnies uitvoerbaar is, asook hoe die multi-straalmodellering op 'n 3-D Systems ThermoJet aangepas is om die proses te stabiliseer. Bestaande beperkings en moontlikhede word uitgelig en verskillende elektroplateringsbenaderings word ondersoek. Die studie ondersoek ook of die waksstruktuur deur 'n aanvanklike geleidingslaag geaktiveer moet word of nie. Verskillende onderdele van die proses is vervaardig, onder andere 'n hitteruiler, 'n verdamper en 'n hervormer. Daarby is meervoudige laag onderdele met verskillende funksies vervaardig deur die proses verskeie kere te herhaal. <![CDATA[<b>Multi-objective optimisation in carbon monoxide gas management at Tronox KZN Sands</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200016&lng=en&nrm=iso&tlng=en Carbon monoxide (CO) is a by-product of the ilmenite smelting process from which titania slag and pig iron are produced. Prior to this project, the CO at Tronox KZN Sands in South Africa was burnt to get rid of it, producing carbon dioxide (CO2). At this plant, unprocessed materials are pre-heated using methane gas from an external supplier. The price of methane gas has increased significantly; and so this research considers the possibility of recycling CO gas and using it as an energy source to reduce methane gas demand. It is not possible to eliminate the methane gas consumption completely due to the energy demand fluctuation, and sub-plants have been assigned either CO gas or methane gas over time. Switching the gas supply between CO and methane gas involves production downtime to purge supply lines. Minimising the loss of production time while maximising the use of CO arose as a multi-objective optimisation problem (MOP) with seven decision variables, and computer simulation was used to evaluate scenarios. We applied computer simulation and the multi-objective optimisation cross-entropy method (MOO CEM) to find good solutions while evaluating the minimum number of scenarios. The proposals in this paper, which are in the process of being implemented, could save the company operational expenditure while reducing the carbon footprint of the smelter.<hr/>Koolstofmonoksied (CO) is 'n newe-produk van die ilmenietsmeltproses waardeur titaniumslak en ru-yster geproduseer word. Voor die uitvoering van hierdie projek is die CO gas wat deur Tronox KZN Sands, Suid-Afrika produseer is, verbrand om daarvan ontslae te raak. Die verbranding het weer koolstofdioksied produseer. By hierdie aanleg word ongeprosesseerde materiale voorverhit met metaangas wat van 'n eksterne verskaffer aangekoop word. Die prys van metaangas het beduidend toegeneem, en die moontlikheid om CO te herbruik in die plek van metaangas is in hierdie studie ondersoek. Weens die variasie in vraag na metaangas, kan die gebruik daarvan nie volledig uitgeskakel word nie; dus moet of CO of metaangas aan sub-aanlegte oor tyd toegeken word. Sodra daar 'n oorskakeling tussen die twee gassoorte plaasvind, moet die toevoerlyne eers gespoel word; en dit veroorsaak verlies van produksietyd. 'n Multidoelwit-optimeringprobleem het dus ontstaan waarin verlies aan produksietyd minimeer word terwyl CO gasgebruik maksimeer word. Hierdie probleem bevat sewe besluitveranderlikes, en scenario's is met rekenaarsimulasie ge-evalueer. Rekenaarsimulasie en die kruis-entropie metode vir multidoelwit-optimering is toegepas om goeie oplossings te verkry terwyl die minimum aantal scenario's evalueer is. Die voorstelle, wat tans in die proses is om implementeer te word, sal die onderneming operasionele koste bespaar en die koolstofspoor verklein. <![CDATA[<b>Optimising steel production shedules via a hierarchical genetic algorithm</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902014000200017&lng=en&nrm=iso&tlng=en This paper presents an effective scheduling in a steel-making continuous casting (SCC) plant. The main contribution of this paper is the formulation of a new optimisation model that more closely represents real-world situations, and a hierarchical genetic algorithm (HGA) tailored particularly for searching for an optimal SCC schedule. The optimisation model is developed by integrating two main planning phases of traditional scheduling: (1) planning cast sequence, and (2) scheduling of steel-making and timing of all jobs. A novel procedure is given for genetic algorithm (GA) chromosome coding that maps Gantt chart and hierarchical chromosomes. The performance of the proposed methodology is illustrated and compared with a two-phase traditional scheduling and a standard GA toolbox. Both qualitative and quantitative performance measures are investigated.<hr/>Effektiewe skedulering van 'n kontinue-giet staalaanleg word voorgehou. Die hoof bydrae van hierdie navorsing is die formulering van 'n nuwe optimiseringsmodel wat regte wêreld situasies beter verteenwoordig, asook 'n hiërargiese genetiese algoritme wat spesifiek aangepas word vir die soek van 'n optimale kontinue-giet skedule. Die optimiseringsmodel is onwikkel deur twee hoof beplanningsfases van tradisionele skedulering te integreer, naamlik die beplan van die giet volgorde en die skedulering van staal vervaardiging en die tydsberekening van alle werkstukke. 'n Nuwe prosedure word voorgestel vir genetiese algoritme chromosoom kodering wat Gantt-kaart en hiërargiese chromosome kombineer. Die voorgestelde metode word geïllustreer en vergelyk met 'n twee fase tradisionele skedulering en 'n standaard genetiese algoritme. Beide die kwalitatiewe en kwantitatiewe prestasiemaatstawwe is ondersoek.