Thesis (PhD (Industrial Engineering))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: This research has its roots in Industrial Engineering, where the premise of improving and managing efficiency, effectiveness, productivity and quality is the most common and accepted source of organisational sustenance and furtherance. This dissertation, however, addresses the evolutionary and revolutionary imperatives of a new paradigm for competitive advantage – innovation. The notion of innovation is considered many things. First and foremost, however, it has become the primary differentiator of organisational competitiveness, rendering it the source of sustained long-term prosperity. What may seem ambiguous in the title of this dissertation is essentially the imperative of every organisation functioning within the competitive domain. Where organisational maturity and innovativeness were traditionally considered antonymous, the assimilation of these two seemingly contradictory notions is fundamental to the assurance of long-term organisational prosperity. Organisations are required, now more than ever, to grow and mature their innovation capability. In working towards the fulfilment of this objective, the Maturity Modelling approach was recognised for its ability to describe organisational progression in terms of innovation capability. An Innovation Capability Maturity Model, with the intention of describing generic and evolutionary plateaus of innovation capability maturity, was developed from a comprehensive literature study. This model was evaluated with an initial case study which led to a rigorous refinement initiative that included further literature study, a mapping and comparison exercise, and a detailed analysis of innovation capability themes using a Latent Dirichlet Allocation-based topic modelling approach. The consolidation of these activities and integration with the initial model resulted in the second version thereof – ICMM v2. This second version was then utilised in an additional 5 case studies that would serve to evaluate and validate the content and structure thereof, but also make a fundamental contribution to the application of the model – captured in the so called Innovation Capability Improvement Methodology. The case studies provide evidence that the content and structure of the ICMM v2, including the approach used to convey these aspects, fulfil their intended purpose by appropriately identifying the innovation capability strengths and weaknesses of the represented organisations. The ICMM v2 and accompanying methodology provides an organisation with a systematic approach for identifying organisational innovation capability strengths and weaknesses and a framework for identifying and prioritising innovation capability improvement opportunities in an organised and coordinated manner. This dissertation concludes with a few fundamental findings pertaining to innovation and a discussion of potential future collaboration and research opportunities. / AFRIKAANSE OPSOMMING: Hierdie navorsingsprojek het sy oorsprong binne die bedryfsingenieursdomain. Bedryfsingenieurswese is primêr gerig op die verbetering en bestuur van doelmatigheid, doeltreffendheid, produktiwiteit en gehalte. Dit is voorts „n vry-algemeen aanvaarde bron van organisatoriese volhoubaarheid en verbetering van maatskappye. Hierdie navorsingsverslag spreek die evolusionêre en revolusionêre vereistes van „n nuwe paradigme vir mededingendheid, naamlik innovasie, aan. Die term innovasie beteken verskillende dinge vir verskillende mense. Dit is sedert die 1930‟s intensief nagevors. Meer onlangs het innovasie ontwikkel tot „n primêre onderskeider van maatskappy-mededingendheid. Dit is vinnig besig om te ontwikkel in „n sleutelbron van volhoubare, langtermyn welvaartskepping. Die titel van hierdie proefskrif mag aanvangklik dubbelsinnig klink, maar dit beskryf eintlik die fundamentele vereistes van elke organisasie wat binne die mededingendheidsdomain funksioneer. Aanvanklik is innovasie en organisatoriese volwassenheid as teenstrydige konsepte beskou. Die versoening van hierdie twee oënskynlike teenstrydige konsepte is egter fundamenteel tot die ontwikkeling van langtermyn organisatoriese mededingendheid en gepaargaande welvaart. Mededingendheid word tans verseker deur die tempo en volhoubaarheid waarmee maatskappye hulle innovasie-vermoeë beoefen en uitbou. Die konsep van volwassenheidsmodelering is identifiseer as „n belangrike element om die innovasie volwassenheid van maatskappye volledig uit te bou, asook om organisatoriese groei in ten opsigte van innovasie-vermoeëns te beskryf. „n Eerste orde innovasie-vermoeë volwassenheidsmodel (ICMM v1) is met behulp van „n uitgebreide literatuur-ondersoek ontwikkel. Hierdie model het ten doel gehad om generiese en evolusionêre plateau‟s van innovasie-vermoeë volwassenheid te beskryf. Die aanvanklike model is geëvalueer met „n gevallestudie waarna dit drasties verfyn is, deur gebruik te maak van „n sekondêre literatuurstudie, die kartering en „n vergelykende evaluering, asook „n gedetailleerde ontleding van innovasie-vermoeë tema‟s. Dit is gedoen deur gebruik te maak van “Latent Dirichlet Allocation”-gebaseerde konsepmodellering. Hierdie aktiwiteite is gekonsolideer en geintegreer met die eerste model in „n weergawe twee, wat bekend staan as ICMM v2. Hierdie weergawe is verder ontplooi in vyf opvolg-gevallestudies wat gebruik is. Die doel hiervan was om die nuwe model te evalueer en valideer ten opsigte van die inhoud en struktuur daarvan. Voorts het die ook „n fundamentele bydra gemaak tot die toepassing van die model waartydens resulutate van die model vervat is in „n sogenaamde innovasie-vermoeë verbeterings metodologie. Die onderskeie gevallestudies het bevestig dat die inhoud en die struktuur van die ICMM v2 hulle aanvanklike doelwitte volledig bereik het deur beide die innovasie-vermoeë sterkpunte en swakpunte van die organisasies te identifiseer en uit te lig. Die ICMM v2 en gepaardgaande metodologie bied aan „n organisasie „n sistematiese benadering tot die identifisering van organisatoriese innovasie-vermoeë sterkpunte en swakpunte. Dit voorsien verder „n raamwerk vir die identifisering en prioritisering van innovasie-vermoeë verbeterings geleenthede binne maatskappye. Hierdie proefskrif word afgesluit met „n aantal fundamentele bevindings met betrekking tot innovasie en „n bespreking van toekomstige samewerking ten opsigte van navorsingsgeleenthede.

Thesis (PhD (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Information on the milling of Ti6Al4V is limited; with most studies concluding that it is not possible to obtain a significant increase in the material removal rate (Qw). Tool wear maps can be a diagnostic instrument for failure analysis. Cutting speed (vc), maximum un-deformed chip thickness (heMax) and the radial immersion percentage (ae/Ø %) are the key variables in understanding the milling of titanium alloys. The objective of this research study was to construct tool wear maps for the milling of Ti6Al4V. This will form the foundation of understanding the cutting demands on the tool, in order to analyse the main wear mechanisms. Remedial actions, which are developed by tool suppliers, can be considered and integrated via this understanding of the failure modes and related mechanisms. Firstly, experimental data from background studies, literature and industry on wear rates and wear mechanisms pertaining to the milling conditions was gathered to construct the tool wear map. Mathematical models describing the wear behaviour for these conditions were also investigated. Secondly, work piece failure maps have been superimposed onto the tool wear maps constructed to understand the global failure boundaries. Experimentation was carried out to validate the constructed maps. The tool wear map could then be used to discuss the observed effects and consider remedial actions. Cutting speed corresponds to the magnitude of the thermal load and heMax represents the mechanical load. The ae/Ø % defines the duration of the exposure to the thermal load at the edge of the cutting tool. This investigation has shown the following issues to be of importance when considering tool performance via the tool wear map approach: 1. The key to designing tool wear maps is to identify the most economic Scheduled Replacement Time (SRT) for the specific components. Knowing the correct SRT makes it possible to optimize the milling conditions so that the cutting tool wears gradually under the cutting conditions, and lasts longer than the economic SRT. 2. Increased vc will decrease tool life (TL). However, in low transverse rupture strength tools there may be a minimum vc below which mechanical overload may occur. Similarly, a local maximum TL (a sweet spot) may exist if there is a phase change in the work piece material. 3. Increased heMax will decrease TL. However, heMax must be kept below a maximum critical value to avoid mechanical overload, but above a minimum critical value to avoid work hardening. 4. Increased ae/Ø % will decrease TL. The best balance of high Qw and economic TL is found with ae/Ø between 30-40% for rough milling. In finish milling the radial cut is limited to 1 mm finishing stock of the work piece. This study revealed the following important factors when considering work piece failure in the milling of Ti6Al4V: 1. Increased vc will reduce the cutting resistance of the work piece and increase Qw. However, vc must be kept below a maximum critical value to avoid work piece material burn, but above a minimum critical value to avoid burring and poor surface finish, due to tool build-up and chip jamming. 2. Increased heMax will increase the cutting resistance of the work piece and increase Qw. The heMax must be kept below a maximum critical value to avoid poor surface finish, poor flatness and parallelism (due to work piece bending). Likewise, heMax must be kept above a minimum critical value to avoid work hardening and burring. The constructed tool wear maps are validated with experimental work. This research work identified safe zones to productively mill Ti6Al4V, while producing components with a sufficient surface integrity. / AFRIKAANSE OPSOMMING: Inligting rondom freeswerk van Ti6Al4V is beperk en volgens meeste studies is dit nie moontlik om ‗n wesenlike toename in die materiaal verwyderingstempo (Qw) te behaal nie. Snybeitel verwerings kaarte kan ‗n diagnostiese hulpmiddel wees tydens analisering van snybeitels. Snyspoed (vc), maksimum onvervormende spaanderdikte (heMax) en radiale snitdiepte persentasie (ae/Ø %) is die sleutel veranderlikes om die freeswerk van Ti6Al4V beter te kan verstaan. Die doel van die navorsingstudie was om snybeitel verweringskaarte vir die freeswerk van Ti6Al4V te bou. Die werk vorm ‗n fondasie om die eise van freeswerk op die snybeitel beter te verstaan. Sodoende kan die hoof verweringsmeganismes analiseer word. Regstellende aksies wat deur snybeitel vervaardigers ontwikkel is, was ondersoek en integreer met die huidige kennis rondom die falingstipe en verwerings meganismes. Aanvanklik was eksperimentele data van agtergrond studies, literatuur en industrie oor die verweringstempos en -meganismes rondom die freeswerk van Ti6Al4V versamel. Hiermee is verweringskaarte gebou. Wiskundige modelle wat die verwering kan beskryf was ook ondersoek. Daarna was werkstuk falingskaarte integreer met die ontwikkeling van die snybeitel verweringskaarte om sodoende die grense in geheel te verstaan. Eksperimentele werk was gedoen om die snybeitel verweringskaarte se uitleg te toets. Sodoende kon die snybeitel verweringskaarte gebruik word om die gedrag van die snybeitel te bespreek en regstellende aksies te ondersoek. Snyspoed (vc) stem ooreen met die grootte van die termiese lading en heMax verteenwoordig die grootte meganiese lading. Die ae/Ø % omskryf die tydperk van blootstelling aan die termiese lading op die snyrand. Die ondersoek het bewys dat die volgende faktore belangrik is wanneer snybeitel prestasie met die snybeitel verweringskaart evalueer word: 1. Die sleutel tot die ontwerp van snybeitel verweringskaarte is om die mees ekonomies beplande vervangingstyd (SRT) vir spesifieke komponente te identifiseer. Sodoende is dit moontlik om die frees toestande te optimaliseer, waaronder die snybeitels geleidelik sal verweer onder die eise en vir ‗n langer tydperk as die ekonomiese SRT sal kan sny. 2. Toename in vc sal snybeitelleeftyd (TL) laat afneem. Snybeitels met ‗n lae dwarsbreuksterkte, kan ‗n minimum vc hê waaronder meganiese oorlading plaasvind. Terselfdertyd, kan ‗n maksimum TL (‗n ―sweet spot‖) bestaan as daar ‗n fase verandering in die werkstuk materiaal plaasvind. 3. Toename in heMax sal TL laat afneem, maar moet laer as ‗n maksimum- en hoer as ‗n minimum kritiese waarde wees, om sodoende meganiese oorlading en werksverharding onderskeidelik te vermy. 4. Toename in ae/Ø % sal TL laat afneem. Die beste balans tussen TL en ae/Ø % is gevind met ae/Ø % tussen 30-40% vir growwe freeswerk. In afrondingsfreeswerk is die radiale snit beperk tot 1 mm van die oorblywende werkstuk. Die ondersoek het bewys dat die volgende faktore belangrik is wanneer werkstukfaling in ag geneem word met snybeitel verweringskaarte: 1. Toename in vc sal die werkstukweerstand geleidelik verminder en Qw laat toeneem. Ongelukkig is vc beperk tot ‗n maksimum kritiese waarde om werkstukfaling te voorkom weens ‗material burn‘. Die snyspoed moet ook hoër as ‗n kritiese waarde wees om werkstukklitsing en swak afronding weens spaander probleme te vermy. 2. Toename in heMax sal die werkstuk weerstand geleidelik vermeerder en Qw laat toeneem. Die heMax is beperk tot ‗n maksimum kritiese waarde om swak werkstuk afronding, weens die buiging van die werkstuk, te vermy. Terselfdertyd moet heMax hoër as ‗n kritiese waarde wees om werkstukverharding en -klitsing te voorkom. Die saamgestelde snybeitel verweringskaarte was bekragtig met eksperimentele werk. Die navorsingswerk het veiligheidsareas identifiseer om Ti6Al4V produktief te frees, sonder om die werkstukoppervlak krities te beïnvloed.

Thesis (PhD (Industrial Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Back pain is a common concern amongst a growing population of people across the world today, where in most cases the pain can become unbearable resulting in major lifestyle adjustments. Seventy to eighty percent of the population of the Western world experiences low-back pain at one time or another. Pain can be produced as a worn disc becomes thin, narrowing the space between the vertebrae. Pieces of the damaged disc may also break off and cause irritation to the nerves signalling back pain. Depending on the severity of a patient’s condition, and after conservative treatment options have been exhausted, a disc replacement surgery (arthroplasty) procedure may be prescribed to restore spacing between vertebrae and relieve the pinched nerve, while still maintaining normal biomechanical movement. Typical complications that are however still observed in some cases of disc implants include: anterior migration of the disc, subsidence (sinking of disc) and lateral subluxation (partial dislocation of a joint). Issues such as function, correct placement and orientation, as well as secure fixation of such a disc implant to the adjacent vertebrae are highly important in order to replicate natural biomechanical behaviour and minimise the occurrence of the complications mentioned. As various imaging and manufacturing technologies have developed, the option for individual, patientspecific implants is becoming more of a practical reality than it has been in the past. The combination of CT images and Rapid Manufacturing for example is already being used successfully in producing custom implants for maxilla/facial and cranial reconstructive surgeries. There exists a need to formalise a process chain for the design and manufacture of custom-made intervertebral disc implants and to address the issues involved during each step. Therefore this study has investigated the steps involved for such a process chain and the sensible flow of information as well as the use of state-of-the-art manufacturing technologies. Strong emphasis was placed on automation of some of the processes as well as the user-friendliness of software where engineers and surgeons often need to work together during this multi-disciplinary environment. One of the main benefits for customization was also investigated, namely a reduction in the risk and potential for implant subsidence. Stiffness values from pressure tests on vertebrae were compared between customized implants and implants with flat endplate designs. Results indicated a statistically significant improvement of customized, endplate matching implants as opposed to flat implant endplates. Therefore it may be concluded that the use of customized intervertebral disc implants with patient specific endplate geometry may decrease the risk and potential for the occurrence of subsidence. / AFRIKAANSE OPSOMMING: Rugpyn is ‘n algemene bekommernis vir ‘n groeiende populasie van mense in die wêreld vandag, waar in meeste gevalle die pyn ondraagbaar kan raak en groot leefstyl aanpassings vereis. Sewentig tot tagtig persent van die populasie in die Westerse wêreld ondervind lae rugpyn op een of ander stadium. Die pyn kan veroorsaak word deur ‘n intervertebrale skyf wat verweer en dunner word, en veroorsaak dat die spasie tussen die vertebrae vernou. Stukkies van die beskadigde skyf mag ook afbreek en irritasie aan die senuwees veroorsaak wat verdere pyn kan veroorsaak. Afhangende van die ernstigheid van ‘n pasiënt se geval, en nadat opsies vir konservatiewe behandeling uitgeput is, kan ‘n skyf vervangings-prosedure (artroskopie) voorgeskryf word om die spasie tussen die vertebrae te herstel en sodoende die geknypte senuwee te verlos. Die skyf vervanging herstel spasiëring tussen vertebrae terwyl die normale biomeganiese beweging ook behoue bly, in teenstelling met ‘n fusieprosedure wat die betrokke vertebrae aanmekaar vasheg en normale beweging belemmer. Tipiese komplikasies wat egter steeds na ‘n skyf vervanging in sommige gevalle waargeneem word sluit in: anterior migrasie van die inplantaat, insinking, sowel as laterale sublukasie (gedeeltelike dislokasie van ‘n gewrig). Faktore soos funksie, korrekte posisionering en orientasie, sowel as vashegting van so ‘n skyf inplantaat tot die aanliggende vertebrale bene is besonder belangrik om natuurlike biomeganiese beweging te herstel en sodoende bogenoemde komplikasies te verminder. Soos wat verskeie beeldings- en vervaardigingstegnologië verbeter het oor die laaste dekade, het die moontlikheid vir individuele, pasiënt-spesifieke inplantate al hoe meer ‘n praktiese realiteit begin word. Die kombinasie van Gerekenariseerde Tomografie (GT), tesame met Snel Vervaardiging word byvoorbeeld reeds suksesvol aangewend tydens die ontwerp en vervaardiging van pasiënt-spesifieke inplantate vir maksilla- en kraniale rekonstruktiewe chirurgie. Daar bestaan egter ‘n behoefte om ‘n formele prosesketting vir die ontwerp en vervaardiging van pasiënt-spesifieke intervertebrale skyf inplantate te ontwikkel en om belangrike faktore tydens elke stap noukeurig te beskryf. Hierdie studie het na die verskillende stappe in die prosesketting gekyk om ‘n sinvolle vloei van informasie en benutting van hoë gehalte vervaardigingstegnologië saam te snoer. Sterk klem was gelê op outomatisering van prosesse asook gebruikersvriendelikheid van sagteware waar ingenieurs en medici dikwels saam moet werk tydens hierdie kruisdissiplinêre omgewing. Een van die hoof verwagte voordele met die gebruik van pasklaar skyf inplantate, naamlik die vermindering van moontlike insinking van die inplantaat in die been, is ook ondersoek. Die ondersoek het druktoetse behels en die vergelyking van ooreenstemmende styfheid tussen inplantate wat die kontoer van die bene volg teenoor gewone plat eindplate. Die resultate was statisties beduidend in die guns van die pasklaar inplantate wat die beenkontoere gevolg het, en bewys dus dat die risiko vir insinking verminder is.

Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2009. / The titanium alloys have found wide application in the aerospace, biomedical and automotive industries. Soaring fuel prices and environmental concerns are the fundamental drivers that intensify the demand situation for titanium. From a machining viewpoint, one of the challenges companies face, is achieving high material removal rates while maintaining the form and function of the part. The ultimate aim for a machining business remains to make parts quickly. Conventional cutting speeds range from 30 to 100 m/min in the machining of Ti-6Al-4V. Milling this alloy faster however is challenging. Although titanium is becoming a material of choice, many of the same qualities that enhance titanium‟s appeal for most applications also contribute to its being one of the most difficult materials to machine. The author explored the potential for Polycrystalline diamond (PCD) inserts in high speed milling of Ti-6Al-4V, by trying to understand the fundamental causes of tool failure. The objective was to achieve an order of magnitude increase in tool life, while machining at high speed, simply by reducing some of the failure mechanisms through different cutting strategies. Tool wear is described as a thermo-mechanical high-cycle fatigue phenomenon. The capability of a higher material removal per tool life is achieved in the case of PCD inserts compared to Tungsten carbide (WC). The average surface roughness produced was relatively low. The collected chips were also analyzed. The work demonstrated progress over the performance reported in current literature. The work confirms that there is a region where a sufficiently high temperature in the cutting zone may contribute to extended tool life, provided that the tool material can withstand these extreme conditions.

Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2006. / This thesis explores the innovation survival issue. As role players in an increasingly global marketplace, businesses acknowledge that regular and constant innovation is the key to remaining competitive. In other words, in order to be successful, businesses are compelled to operate and produce products that will satisfy the changing market requirements and exploit new technology opportunities. The study also investigates the difficulties and risks associated with innovation activities. Secondly, with the goal of addressing the identified problems and risks, a study is made of formal innovation models. The different innovation models are then compared with each other and plotted on a general Innovation Landscape. The populated Innovation Landscape thus serves as a positioning guide to innovators, so that they can select the best-suited innovation model for a specific industry and project. A case study is then undertaken to test the level of applicability and the possible support that formal innovation models can offer to a real industrial problem. The case study focuses on the front-end of innovation and the formal innovation model studied was the W-Model. The W-Model is also critically evaluated, based on the results of the case study, in order to propose improvements so that it can better support future industry innovation applications.

Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: The demand in air travel is continuously increasing. In order to handle this increase in demand, airports need to physically expand or the management of the airports needs to improve. When the demand at OR Tambo International Airport gets too high, more passengers will need to travel to Lanseria International Airport, which will therefore need to be expanded. The study was done in collaboration with Virtual Consulting Engineers, who decided that the concept of Atlanta International Airport in Georgia, USA, which is ranked the busiest airport in the world, will be used in this expansion. The aim of the study was to minimise passenger walking distances and waiting times at Lanseria International Airport. This was done by comparing di erent airport apron layouts, using simulation, and improving the aircraft gate assignment, using the cross-entropy method. Four di erent designs of airport layouts, all based on that of Atlanta International Airport, were compared in the study. A model of each was developed using simulation. The performance measures used to compare the designs included 1) the average walking distance of arriving and departing passengers at the airport, 2) the average time spent at the airport by arriving and departing passengers, 3) the average distance travelled by aircraft at the airport, 4) the average time by which each aircraft is delayed and 5) the average number of aircraft present at the airport. The walking distance of arriving and departing passengers was largely a ected by the way in which ights were assigned to gates. The gates at the airport are of three di erent sizes: small, medium and large. Small aircraft can park at any of the gates, while medium aircraft can only park at medium or large gates and large aircraft can only park at large gates. Three rules for the ight-to-gate assignment process were developed. In the rst two rules an arriving ight was assigned to the available, suitable gate closest to the terminal building. The constraint that small aircraft cannot be assigned to medium or large gates if there are small gates available and that medium aircraft cannot be assigned to large gates if there are medium gates available, was used in Rule 1 and not in Rule 2. In the third rule, metaheuristic optimisation was used to determine a ight-to-gate assignment schedule with the objective of minimising the passenger walking distances. This metaheuristic optimisation was performed in real-time and was thus repeated every time a delay occurred at the airport. The background of airports, simulation, metaheuristics and relevant case studies were investigated in the literature review. The simulation and metaheuristic optimisation models were then developed. The results identi ed the best of the four designs that were compared. It was also concluded that the use of metaheuristic optimisation, using the cross-entropy method, results in a reduction in passenger walking distances at the airport. / AFRIKAANSE OPSOMMING: Die aantal lugpassasiers neem aanhoudend toe en om in staat te wees om hierdie toename in vraag te hanteer moet lughawens sies uitbrei of die bestuur van die lughawens moet verbeter. Wanneer die vraag by OR Tambo Internasionale Lughawe te hoog raak, gaan meer mense na Lanseria Internasionale Lughawe moet reis. Die lughawe sal dan dus moet uitbrei. Die studie is in samewerking met Virtual Consulting Engineers gedoen. Hulle het besluit dat die konsep van Atlanta Internasionale Lughawe in Georgia in die VSA, wat die besigste lughawe in die w^ereld is, gebruik sal word in die uitbreiding Lanseria Internasionale Lughawe. Die doelwit van die studie was om die loopafstand en die wagtyd van passasiers op Lanseria Internasionale Lughawe te minimeer. Die doelwit is bereik deur verskillende lughawe uitlegte te vergelyk met behulp van simulasie en deur die toekenning van vlugte aan hekke te verbeter, deur gebruik te maak van die "cross-entropy" metode. Die konsep van Atlanta Internasionale Lughawe is gebruik om vier verskillende lughawe uitlegte te ontwerp. Simulasie is gebruik om die vier ontwerpe te vergelyk op grond van 1) die gemiddelde loopafstand van passasiers wat aankom en vertrek, 2) die gemiddelde tyd wat passasiers wat aankom en vertrek spandeer op die lughawe, 3) die gemiddelde afstand wat vliegtuie a ^e op die lughawe, 4) die gemiddelde tyd wat vliegtuie vertraag word, 5) die gemiddelde hoeveelheid vliegtuie teenwoordig op die lughawe. Die loopafstand van passasiers wat aankom en vertrek is grootliks beinvloed deur die manier waarop vliegtuie aan hekke toegeken is. Die hekke op die lughawe is klein, medium of groot. 'n Klein vliegtuig mag by 'n klein, medium of groot hek parkeer, 'n medium vliegtuig mag by 'n medium of groot hek parkeer en 'n groot vliegtuig mag net by 'n groot hek parkeer. Drie reels waarvolgens vliegtuie aan hekke toegeken kan word is ontwikkel. In die eerste twee reels word 'n vliegtuig wat aankom aan die beskikbare hek naaste aan die terminaal gebou toegeken as die hek geskik is vir die vliegtuig. In die eerste reel is die beperking dat klein vliegtuie nie aan medium en groot hekke toegeken mag word as daar klein hekke beskikbaar is nie en dat medium vliegtuie nie aan groot hekke toegeken mag word as daar medium hekke beskikbaar is nie, ingesluit. Hierdie beperking is nie in die tweede reel ingesluit nie. In die derde reel is metaheuristiek optimering gebruik om vliegtuie aan hekke toe te ken. Die doelwit van die metaheuristiek optimering was om die loopafstand van die passasiers te verminder. Elke keer as 'n vliegtuig op die lughawe vertraag was, is die optimering proses is herhaal. Die agtergrond van lughawens, simulasie, metaheuristieke en gevalle studies is bestudeer in die literatuur studie. Daarna is die simulasie en metaheuristiek optimering modelle ontwikkel. Die resultate van die studie het aangedui watter een van die vier lughawe ontwerpe die beste is. Dit is ook beslis dat die gebruik van metaheuristiek optimering, en spesifi ek die "cross-entropy" metode, die loopafstand van passasiers op die lughawe verminder.

Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Cash can be seen as a fast moving consumer good. Approaching cash as inventory within the ATM cash management environment of a South African retail bank, provided the opportunity to apply well known industrial engineering techniques to the financial industry. This led to the application of forecasting, inventory management, operational research and simulation methods. A forecasting model is designed to address the multiple seasonalities and calendar day effects that is prevalent in the demand for cash. Special days, e.g. paydays, lead to an increase in demand for cash. The weekday on which the special day falls will also influence the demand. The multiplicative Holt-Winters method is combined with an improvised distribution method to determine the demand for cash for the region and per ATM. Reordering points are calculated and simulated to form an understanding of the effect this will have on the ATM network. Direct replenishment and the traveling salesman problem is applied and simulated to determine the difference in using one or the other. Various simulation models are build to test the operational and financial impact when certain variables are amended. It is evident that more work is required to determine the optimal combination of variable values, i.e. forecasting frequency, aggregate forecasting or individual forecasting, reorder levels, loading levels, lead times, cash swap or cash add, and the type of transportation method. Each one of these are a science in itself and cannot be seen (calculated) in isolation from the other as a change in one can affect the overall operational efficiency and costs of the ATM network. The thesis proves that significant cost savings is possible, compared to the current set-up, when applying industrial engineering techniques to a geographical ATM network within South Africa. / AFRIKAANSE OPSOMMING: Kontant kan gesien word as vinnig bewegende verbruikersgoedere. Deur kontant te benader as voorraad binne die ATM kontant bestuur omgewing van ’n Suid Afrikaanse kleinhandelsbank, het dit die geleentheid geskep om bekende bedryfsingenieurstegnieke toe te pas in die finansiële industrie. Dit het gelei tot die toepassing van vooruitskatting, voorraadbestuur, operasionele navorsing en simulasie metodes. ’n Vooruitskattingsmodel is ontwerp om die verskeie seisoenaliteite en kalenderdae effekte wat deel uitmaak van die vraag na kontant aan te spreek. Spesiale dae, bv. betaaldae, lei tot ’n toename in die vraag na kontant. Die weeksdag waarop die spesiale dag voorkom sal ook ’n invloed hê op die vraag. Die multiplikatiewe Holt-Winters metode is gekombineer met ’n geïmproviseerde verspreidingsmetode om die vraag na kontant vir die streek en per ATM the bepaal. Bestellingsvlakke is bereken en gesimuleer om ’n prentjie te skep van die invloed wat dit op die ATM netwerk sal hê. Direkte hervulling en die handelsreisigerprobleem is toegepas en gesimuleer om die verskille te bepaal tussen die gebruik van of die een of die ander. Veskeie simulasie modelle is gebou om die operasionele en finansiële impak te toets, wanneer sekere veranderlikes aangepas word. Dit is duidelik dat meer werk nodig is om die optimale kombinasie van veranderlike waardes te bepaal, bv. vooruitskatting frekwensie, totale vooruiskatting of individuele vooruitskatting, bestellingsvlakke, leitye, kontant omruiling of kontant byvoeging, en die tipe vervoermetode. Elkeen van hierdie is ’n wetenskap op sy eie en kan nie in isolasie gesien en bereken word nie, want ’n verandering van een se waarde kan die hele operasionele doeltreffendheid en kostes van die ATM netwerk beïnvloed.

Thesis (MScEng)--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Can one measure the value of knowledge sharing? How does one assess the effectiveness of a knowledge network with regard to supporting knowledge sharing? These are pertinent questions that knowledge managers are faced with, because geographically dispersed organizations rely on knowledge networks to integrate its dispersed knowledge. These questions must be understood in the context of a knowledge management approach, for the approach determines how one navigates the complex landscape of knowledge sharing. This complexity is driven by the social dynamics that exist between organizational members. If the intricacies of these social dynamics can be highlighted, it will assist management in deciding which interventions to implement to increase a knowledge network’s effectiveness. Firstly, a pragmatic approach to knowledge management proposes that management can switch between a bottom-up and top-down view of knowledge sharing in a knowledge network. Secondly, management requires a vehicle to implement the pragmatic approach. The proposed vehicle is the knowledge network framework, for it plays a central role in the design, implementation and maintenance of a knowledge network. Finally, the embeddedness-measuring framework is developed to analyze the social dynamics between knowledge network members and the content they share amongst one another. The implementation of this framework allows for the analysis of interviews that were conducted in a case study at A Chemicals Company (ACC). Five communities of ACC’s knowledge network are investigated and the results emphasize the dynamics of knowledge sharing between network members. The implications of the results are as follows: • A navigation system is proposed that enables the implementation of the pragmatic approach. • A schedule for the evaluation of a knowledge network enables management to assess the effects of interventions. / AFRIKAANSE OPSOMMING: Kan die waarde van die proses om kennis te deel, gemeet word? Hoe word ‘n kennis-netwerk se doeltreffendheid gemeet met betrekking tot die ondersteuning wat dit bied vir netwerk-lede om hul kennis te deel? Dit is die tipe vrae wat kennis-bestuurders mee gekonfronteer word, want organisasies wat geografies versprei is maak staat op kennis-netwerke om verspreide kennis te integreer. Om hierdie vrae te verstaan, moet dit gesien word in die konteks van 'n kennisbestuur-strategie. Die kennisbestuur-strategie bepaal hoe ‘n mens die kompleksiteit van kennis-skepping en -uitruiling benader. ‘n Groot faktor wat dié kompleksiteit beïnvloed, is die sosiale dinamika tussen netwerk-lede. Daar word dus geredeneer, dat as sin gemaak kan word van dié dinamika, bestuur se vermoë om in te gryp in die kennis-netwerk verbeter sal word. Gevolglik kan die doeltreffendheid van ‘n kennis-netwerk verbeter word. Eerstens word die pragmatiese benadering tot kennisbestuur voorgestel. Dié strategie gee bestuur die vermoë om te wissel tussen ‘n top-down benadering en ‘n bottom-up benadering tot kennisbestuur. Tweedens word die kennis-netwerk raamwerk bespreek. Hierdie raamwerk beskryf die ontwerp, implimentering en instandhouding van ‘n kennis-netwerk. Dit bied bestuur die vermoë om die pragmatiese benadering te volg. Ten slotte word die geïntegreerde metings raamwerk ontwikkel. Hierdie raamwerk stel mens instaat om ‘n analise te doen van die sosiale dinamika tussen netwerk-lede en die inhoud wat hulle met mekaar deel. Die geïntegreerde metings raamwerk word gebruik om onderhoude te analiseer van die lede van ‘n kennis-netwerk gevallestudie. Hierdie gevallestudie is gesentreer rondom die bedryf A Chemical Company (ACC) se kennisnetwerk. Vyf kennis-uitruil gemeenskappe van ACC se kennis-netwerk word ondersoek. Die resultate beklemtoon die dinamika tussen netwerk-lede in die proses om kennis uit te ruil. Die gevolgtrekking van die navorsing is soos volg: • ‘n Strategie word ontwikkel wat die implimentering van die pragmatiese benadering tot kennis-bestuur beskryf. • ‘n Skedule vir die evaluering van ‘n kennis-netwerk word voorgestel wat bestuur die vermoë bied om die gevolge van veranderinge in ‘n kennisnetwerk te assesseer.

Thesis (MScEng)--Stellenbosch University 2012 / ENGLISH ABSTRACT: Reverse engineering (RE) has emerged as an important tool in the design stages of a product. The demand for better performance of hardware and software has spawned many different technologies that fall under RE. The diversity of technologies is linked to the different application areas of industry. It is critical to understand what the exact capability of each individual technology is, in order to choose the appropriate RE system. The objective of this study is to develop capability profiles of different RE technologies available, such as: Coordinate Measuring Machine, Articulated Arm (Cimcore), Non-contact scanner (GOM), and contact scanner (Renishaw). To achieve the objective, the different characteristics of each technology are measured and quantified. A capability profile can be regarded as defined criteria that represent the performance of a RE technology and in this study, is defined by quantifying the following characteristics:  Accuracy  Repeatability  Speed of Measurement  Work Envelope  User-friendliness. The significance of developing these capability profiles is so that they may be compared to one another. This is important, especially for the accuracy criterion, as each technology is manufactured by a different company, making an acceptable accuracy comparison amongst the different technologies impossible. The study also suggests an evaluation tool which will help a decision maker choose the appropriate technology for a specified objective. Guidelines are also given to potential end users of RE technologies on how they should go about acquiring the right system. On a more general level, the study contributes to research in recent trends, in the RE industry in terms of application, hardware, software and the selection of RE systems. By developing these capability profiles, the study aims to contribute to its value in academia, as well as for industry partners and potential RE end-users. / AFRIKAANSE OPSOMMING: RE het ontwikkel as n belangrike hulpmiddel in die ontwerp fase van ‘n produk. Die aanvraag na beter prestasie van hardeware en sagteware het gelei tot die ontwikkeling van baie verskillende tegnologie. Die diversiteit van die tegnologie gaan hand aan hand met die verskillende toepassings areas in die industrie. Dit is belangrik om die spesifieke eienskappe van elke individuele tegnologie te verstaan om die regte RE sisteem te kies. The doel van hierdie studie is om die vermoë profiele van die verskillende beskikbare RE tegnologie te ontwerp: Coordinate Measuring Machine, Articulated Arm (Cimcore), nie-kontak skandeerder (GOM) en kontak skandeerder (Renishaw). Die verskillende eienskappe van elke tegnologie word gemeet en gekwantifiseer. ‘n Vermoë profiel kan gesien word as ‘n vaste kriteria wat die prestasie van die RE tegnologie verteenwoordig en in hierdie studie word dit gedefinieer deur die volgende eienskappe:  Akkuraatheid  Herhaalbaarheid  Spoed van meeting  Meet volume  Gebruikers-vriendelikheid Die relevansie van die ontwikkeling van hierdie vermoë profiele is dat dit wedersyds vergelyk kan word. Dit is belangrik, spesifiek vir die akkuraatheids kriteria, omdat elke tegnologie by ‘n verskillende maatskappy vervaardig word. ‘n Aanvaarbare akkuraatsheid vergelyking onder die verskillende tegnologie is dus onmoontlik. Die studie stel ook ‘n evaluasie hulpmiddel voor wat die besluitnemer sal lei om die mees toepaslike tegnologie te kies vir die spesiefieke doeleindes. Verder word riglyne aan die potensiele gebruikers van RE tegnologie gegee oor hoe om te werk te gaan om die regte sisteem te kies indien die tegnologie nie in besit is nie. Op ‘n meer algemene vlak dra die studie tot navorsing by deur die nuutste tendense in toepassing, hardeware, sagteware en die keuse van RE sisteme in die RE industrie te beskryf. Deur hierdie vermoë profile te ontwikkel beoog die studie om waarde toe te voeg aan die akademie, vennote in die industrie en potensiele RE gebruikers.

Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The current food system is failing to effectively serve the urban poor. The modernisation and globalisation of the food system solves one set of problems, regarding food security, but at the same time it results in the creation of other complex challenges. Technically the food system ensures adequate food availability on a macro scale, but the structure of the system contributes to the creation of food deserts. Food deserts are areas in which there is a lack of food retail outlets where affordable, nutritious food is available. Communities living in these areas usually struggle to obtain a nutritious diet and the residents are characterised as poverty-stricken and of a poor nutritional status. The aim of this research is to support local authorities in the management and strategic planning of community food security. The research was conducted in Avian Park, a low-income community in the Breede Valley of the Western Cape, South Africa. The food retail environment of Avian Park was investigated to determine the availability and accessibility of food in the community. Furthermore, a system dynamics model was developed to identify those areas in the food system which need attention, in order to achieve greater food security. In addition strategies are suggested to improve community food security; specifically for Avian Park. These research outcomes, however, also serve as a general guideline for managing food security in low-income communities more effectively. / AFRIKAANSE OPSOMMING: Die huidige voedsel sisteem slaag nie daarin om arm mense in stede effektief te dien nie. Die ontwikkeling en globalisering van die voedsel sisteem los een stel probleme rondom voedselsekerheid op, maar skep terselfdetyd ander komplekse uitdagings. Tegnies verseker die voedsel sisteem die beskikbaarheid van genoegsame voedsel op 'n makro skaal, maar die struktuur van die sisteem dra by tot die ontwikkeling van “food deserts.” “Food deserts” is areas waar daar „n tekort aan voedsel kleinhandel afsetpunte is waar daar bekostigbare, voedsame kos beskikbaar is. Gemeenskappe wat in hieride areas leef sukkel gewoonlik om „n voedsame dieet te bekom en die inwoners word geken aan armoede en 'n ongewenste voedingstatus. Die doel van hierdie navorsing is om plaaslike owerhede te ondersteun om gemeenskap voedselsekerheid meer efektief te bestuur. Die navorsing was in Avian Park, „n lae-inkomste gemeensakp in die Breede Vallei van die Wes-Kaap, Suid-Afrika uitgevoer. Die voedsel kleinhandel omgewing van Avian Park is ondersoek om die voedsel beskikbaarheid en toegangklikheid te bepaal. Verder is „n “system dynamics” model ontwikkel om die areas in die voeldsel sisteem wat aandag verg, ten einde voedselsekuriteit te bekom, te identifiseer. Ten slotte word daar strategieë voorgestel om gemeenskap voeldselsekuriteit in Avian Park te verbeter. Hierdie navorsingsuitkomste dien egter ook as algemene riglyne om lae inkomste gemeenskappe se voedselsekerheid meer effektief te bestuur.