Issue 1, 2013 South African Journal of Industrial Engineering - Volume 24,
Volume 27 (2016) Volume 26 (2015) Volume 25 (2014) Volume 24 (2013) Volume 23 (2012) Volume 22 (2011) Volume 21 (2010) Volume 20 (2009) Volume 19 (2008) Volume 18 (2007) Volume 17 (2006) Volume 16 (2005) Volume 15 (2004) Volume 14 (2003) Volume 13 (2002) Volume 24,
Prof JP Botha (15 April 1928 - 27 March 2013) : obituary
South African Journal of Industrial Engineering 24 (2013)
Prof Johan Botha, who spent the greater part of his adult life as an academic in the Faculty of Engineering at the University of Pretoria, recently passed away.
An unlikely suitor : industrial engineering in health promotion
South African Journal of Industrial Engineering 24, pp 1 –13 (2013)
Primêre gesondheidsorg is die grondslag vir transformasie van gesondheidsorg in Suid-Afrika. Die primêre gesondheidsorgsisteem word gebaseer op vyf pilare waarvan een die bevordering van gesondheid behels. Die beginsels van gesondheidsbevordering hou voor bevordering van gesondheid en welstand in gemeenskappe die las van siekte op beide die primêre en hoër orde gesondheidsisteme sal verlig. Die uitdaging in Suid-Afrika is egter dat die faktore wat gemeenskappe raak dikwels hulle vermoê om hulle gesondheid te beheer inhibeer. Daarbenewens gaan die gesondheidsbevorderingsfunksie binne klinieke mank aan hulpbronne: elke person wat hierdie rol vervul bedien tipies &apos;n verarmde gemeenskap van tot 50 000 persone. Hierdie artikel ondersoek die aanwending van die beginsels van die bedryfsingenieurswese om impak gesondheidsbevordering te verbeter. Vyf klinieke in die Ekurhuleni Munisipaliteit in Gauteng is bestudeer. Die resultate toon gebrek aan konsekwentheid tussen die klinieke. Algemene problem hou verband met die gebrek aan standard prosesse, structure, maatstawwe, hlpbronne en opleiding. Voorstelle ter verbetering word voorgehou soos gebasser op die beginsels van die bedryfsingenieurswese.
B. De Wet and
South African Journal of Industrial Engineering 24, pp 14 –28 (2013)
Die suksestempo van sagteware ontwikkelingsprojekte oor die wêreld is tans laag en volg die tendens reeds vir &apos;n aantal dekades. Die toepassing van projek risikobestuur het die suksestempo vir sagtware projekte wel verbeter in ontwikkelde lande. Hierdie studie het &apos;n ondersoek gedoen om te bepaal of die suksestempo van sagteware projekte in Suid Afrika ook laag is, en of die toepassing van risikobestuur vir sagteware projekte die suksestempo kan verbeter. Die resultate van die studie het aangetoon dat die gemiddelde suksestempo van sagteware projekte in Suid Afrika wel baie laag is, en dat die projekte dikwels soorgelyke risiko&apos;s ervaar as in die ontwikkelde wêreld. Die studie het ook bevind dat sagteware projekte waar risikobestuur toegepas is beter presteer het as projekte sonder risikobestuur. Die studie het ook aangedui dat die meerderheid sagteware maatskappye in Suid Afrika gebruik maak van ad hoc risikobestuur prosedures wat intern ontwikkel is, en dus nie formele prosedures gebruik nie.
South African Journal of Industrial Engineering 24, pp 29 –49 (2013)
Government institutions need to assess how well they meet the needs of their customers, and what their customers think about the quality of the services they provide. This is aligned with the &apos;Batho Pele&apos; principle of the South African government. The SERVQUAL scale, augmented with a qualitative survey, was used to determine how the National Home Builders Registration Council (NHBRC) is perceived by its clients, which key factors drive such perceptions, and whether the perceptions are consistent across the different client groups of this regulatory institution. The complementary role of qualitative data in illuminating issues driving quantitative results is highlighted. Service quality scores are computed for the NHBRC. The convergence of opinions of different customer groups was studied using correlation analysis. The significance of service quality perception gaps was tested using the multivariate analysis of variance, and the reliability of the SERVQUAL scale was examined using exploratory factor analysis. It was observed that by improving the feedback mechanism of the NHBRC, their clients&apos; customer service quality perceptions could be enhanced.
South African Journal of Industrial Engineering 24, pp 50 –67 (2013)
Lae-tegnologie ondernemings, soos dié in die meubelvervaardingingsbedryf, het geen raamwerk of metodologie om hulle te lei in die suskesvolle aanwending van tegnologie met die oog daarop om hulle meer mededingend te maak nie. Die doel van hierdie artikel is om te illustreer hoe &apos;n tegnologiestrategieraamwerk ontwikkel is om klein- tot medium-grootte meubelvervaardigers te help om meer mededingend te wees. Hierdie artikel bied dus &apos;n geïntegreerde tegnologiestrategieraamwerk aan wat bestuur sal help om hulle onderneming-strategie met hul tegnologievereistes te integreer en sodoende meer mededingend te wees.
The Toyota Production System&apos;s fundamental nature at selected South African organisations - a learning perspective
F.D. Nortje and
South African Journal of Industrial Engineering 24, pp 68 –80 (2013)
The Toyota Production System (TPS) has been cited as being the pinnacle of continuous improvement approaches in manufacturing organisations, and many models of the TPS are well known. However, some authors question the effectiveness of established approaches, and propose Bateson&apos;s theory of learning to be an effective way to explain phenomena like the TPS. This paper investigates the degree to which TPS elements are found in selected South African organisations. It constructs a model of the TPS using Bateson&apos;s theory of learning as a framework. The adoption of TPS elements is investigated through multiple qualitative case studies in seven organisations. The analysis follows a clustering and cross-case approach combined with pattern matching. While elements vary in their use, the selected organisations practise the TPS substantially less than the model advocates, with the model being least practised in low volume job/batch manufacturing. Product-process differences and higher levels of the TPS model may clarify peculiar outcomes.
Die Toyota Vervaardigingstelsel (TPS) word deur sommige beskou as die toppunt van volgehoue-verbetering metodes tans in gebruik deur veral vervaardigingsmaatskappye, en teorieë oor die stelsel is welbekend. Sommige kenners reken egter die huidige verstaan van die TPS skiet tekort in sekere aspekte, en stel Bateson se teorie oor hoe mense leer voor as &apos;n beter manier om &apos;n fenomeen soos die TPS te verstaan. Hierdie artikel ondersoek die voorkoms van die basiese aard van die TPS by geselekteerde Suid-Afrikaanse organisasies. Bateson se teorie word as &apos;n raamwerk gebruik om &apos;n model van die TPS op te stel. Kwalitatiewe gevallestudies, waaraan sewe organisasies deelneem, word gebruik om data in te samel. Die analise volg &apos;n groepering en kruisondersoek benadering tesame met patroon-ontleding om tot &apos;n gevolgtrekking te kom. Elemente van die model word wisselend toegepas en aansienlik minder as wat die TPS model voorhou, met die minste toepassing gevind in lae volume / lot-vervaardiging omgewings. Interessante uitkomste word moontlik verduidelik deur produk-proses vergelykings asook die toepassing van die hoër vlakke van die TPS model soos opgestel.
South African Journal of Industrial Engineering 24, pp 81 –90 (2013)
As industry moves toward an era of complete automation and &apos;mass customisation&apos;, automated guided vehicles (AGVs) are used as material handling systems. However, the current techniques that provide navigation, control, and manoeuvrability of automated guided vehicles threaten to create bottlenecks and inefficiencies in manufacturing environments that strive towards the optimisation of part production.
Outomaties geleide voertuie (OGVs) word gebruik in materiaalhanteringstelsels soos wat industrie na &apos;n era van outomatisering en &apos;massa aanpassing&apos; beweeg. Die huidige tegnieke wat sorg vir navigasie, beheer, en beweegbaarheid, hou die bedreiging van bottelnekke en ondoeltreffendheid in vir vervaardigingsomgewings wat streef na optimisering van onderdeelproduksie.
Hierdie artikel hou &apos;n gedesentraliseerde lokaliseringstegniek voor vir &apos;n OGV sonder enige nie-holonomiese beperkings. Implementering van dié voertuie in die materiaalhantering-stelsel van &apos;n rekenaar geïntegreerde vervaardigingsomgewing sal eienskappe soos robuustheid, doeltreffendheid, buigbaarheid, en gevorderde beweegbaarheid verbeter.
South African Journal of Industrial Engineering 24, pp 91 –97 (2013)
Infra-red optical components are made mainly from hard and brittle materials such as germanium and silicon. Silicon machining is characterised by some difficulties when ultra-high precision machined by mono-crystalline single-point diamond. Accelerated tool wear and machined-surface deterioration may take place if the machining parameters are not properly selected. In this study, we conducted a machining test on an ultra-high precision machine tool, using ductile regime cutting conditions when fabricating a convex surface on a silicon lens of aperture of 60 mm diameter, and using a mono-crystalline diamond. It was found that the cutting conditions for shaping a convex surface of 500 mm radius resulted in good form accuracy. However, more attention should be paid to optimising the holding force of the vacuum chuck employed.
Infrarooi optiese komponente word hoofsaaklik van harde, bros materiale soos germanium en silikon gemaak. Ultra-hoë akkurate masjinering van silikon met &apos;n mono-kristallyne enkelpunt diamantbeitel gee aanleiding tot verskeie probleme. Versnelde beitelslytasie en degradering van die masjineringsoppervlak kan plaasvind indien die masjineringsparameters nie behoorlik gekies word nie. In hierdie studie het ons &apos;n masjineringstoets uitgevoer met &apos;n ultra-hoë akkurate masjineringstelsel, waar rudraaiwerk gebruik is om die konvekse oppervlak van &apos;n silikonlens met &apos;n 60 mm opening met &apos;n mono-kristallyne enkelpunt diamantbeitel te masjineer. Daar is bevind dat die snytoestande wat gebruik is om die konvekse oppervlak met 500 mm radius te vorm, tot goeie vorm-akkuraatheid gelei het. Meer aandag moet egter gegee word aan die optimering van die vashoukrag van die vakuum-kloukop wat gebruik word.
Chi-Chun Lo and
South African Journal of Industrial Engineering 24, pp 98 –106 (2013)
The collection of real-time traffic information is an important part of intelligent transportation systems. In particular, cellular floating vehicle data (CFVD) technology has become increasingly widespread, and more and more popular for measuring and forecasting real-time traffic information, based on anonymous sampling of the positions of mobile phones. This study proposes an analytical model to analyse the speed-reporting rates - based on communication behaviour, traffic conditions, and the two consecutive fingerprint-positioning locations from the call arrival and call completion signals of the same call - for a feasibility evaluation of CFVD.
Die versamel van werklike, intydse verkeersinligting is &apos;n belangrike deel van intelligente vervoersisteme. In die besonder het sellulêre bewegende voertuigdata tegnologie toenemend algemeen en populêr geword vir die meting en vooruitskatting van intydse verkeersinligting. Dit word gebaseer op die anonieme monsterneming van die posisie van seltelefone. Hierdie artikel hou &apos;n analitiese model voor vir die ontleding van die tempo waarteen snelheid gerapporteer word soos gebaseer op die kommunikasiegedrag, verkeerstoestande en twee opeenvolgende vingerafdruk posisioneringsliggings van die oproep aankoms- en voltooiingseine soos ontvang vir dieselfde oproep - om sodoende die tegnologie te evaluaeer vir uitvoerbaarheid.
Automatic target recognition on land using three dimensional (3D) laser radar and artificial neural networks
South African Journal of Industrial Engineering 24, pp 107 –120 (2013)
During combat, measuring the dimensions of targets is extremely important for knowing when to fire on the enemy. The importance of identifying a known target on land emphasizes the importance of techniques devoted to automatic target recognition. Although a number of object-recognition techniques have been developed in the past, none of them have provided the desired specifics for unidentified target recognition. Studies on target recognition are largely based on images that assume that images of a known target can be readily viewed under any circumstance. But this is not true for military operations conducted on various terrains under specific circumstances. Usually it is not possible to capture images of unidentified objects because of weather, inadequate equipment, or concealment. In this study, a new approach that integrates neural networks and laser radar has been developed for automatic target recognition in order to reduce the above-mentioned problems. Unlike current studies, the proposed model uses the geometric dimensions of unidentified targets in order to detect and recognise them under severe weather conditions.
Die bepaling van teikenafmetings is van besondere belanggedurende gevegte sodat vuurtydstipte sodoende vasgelê kan word. In hierdie opsig word outomatiese uitkenning van teikentipe dus ook belangrik. Laasgenoemde tegnieke het desnieteenstaande nie besonder presteer met die uitkenning van vreemdeteikentipes nie. Terreintoestande, weers-omstandighede, swak waarnemingstoerusting en kamoeflering speel in die verband ook &apos;n rol. Nuwerwetse toerusting wat gebruikmaak van neurale netwerke laserradar word voorgehou as &apos;n oplossing vir die vraagstuk onder uiteenlopende omgewingstoestande.
Solving a novel multi-skilled project scheduling model by scatter search
P. Shahnazari-Shahrezaei and
South African Journal of Industrial Engineering 24, pp 121 –135 (2013)
A multi-skilled project scheduling problem (MSPSP) has generally been presented to schedule information technology projects in deterministic conditions. The contribution of this model is to consider the resources, called &apos;staff members&apos;. These members are regarded as valuable, renewable, and discrete resources with different multiple skills. The different skills of staff members, as well as the project network&apos;s activity requirement of different skills, cause this problem to become a special type of multi-mode resource-constrained project scheduling problem (MM-RCPSP), with a huge number of modes. Taking into account the importance of this issue and the few studies performed on this problem, a novel mathematical model for the MSPSP is presented. Since the complexity of this problem is NP-hard, an efficient scatter search (SS) algorithm is developed to solve such a difficult problem. This proposed SS is capable of generating optimised solutions in small sizes, and the excellent solutions in large sizes are compared with the solutions reported by a proposed Tabu search (TS) algorithm.
&apos;n Veeldoel projekskeduleringsvraagstuk (MSPSP) word voorgehou vir skedulering onder deterministiese toestande van inligtingstegnologieprojekte. Die model word aangewend vir hulpbronne genaamd "personeellede". Die bronne is waardevol, hernubaar, diskreet en beskik oor uiteenlopende vaardighede. Die eienskappe van die vraagstuk berus by uiteenlopendheid. Vir die voorafgaande omstandighede word &apos;n nuwe model geskep vir die hantering van eienaardighede. Aangesien die problem NP-moeilik is, word &apos;n doeltreffende spreisoek-algoritme gebruik met groot sukses.
H. Esfandiar and
South African Journal of Industrial Engineering 24, pp 136 –151 (2013)
In this paper, based on the Voigt-Kelvin constitutive model, nonlinear dynamic modelling and state space representation of a viscoelastic beam acting as a flexible robotic manipulator is investigated. Complete nonlinear dynamic modelling of a viscoelastic beam without premature linearisation of dynamic equations is developed. The adopted method is capable of reproducing nonlinear dynamic effects, such as beam stiffening due to centrifugal and Coriolis forces induced by rotation of the joints. Structural damping effects on the model&apos;s dynamic behaviour are also shown. A reliable model for a viscoelastic beam is subsequently presented. The governing equations of motion are derived using Hamilton&apos;s principle, and using the finite difference method, nonlinear partial differential equations are reduced to ordinary differential equations. For the purpose of flexible manipulator control, the standard form of state space equations for the viscoelastic link and the actuator is obtained. Simulation results indicate substantial improvements in dynamic behaviour, and a parameter sensitivity study is carried out to investigate the effect of structural damping on the vibration amplitude.
Customer familiarity with new industrial product technology and its influence on adoption : the case of De Beers diamond extraction equipment
A. Nabbie and
South African Journal of Industrial Engineering 24, pp 152 –166 (2013)
An investigation was conducted into the influence of industry customers&apos; familiarity with new technology on their decisions when purchasing discontinuous industrial products. This was done in the context where the supplier and customer organisations are entities in the same company. Even in this favourable context, continuous products remained successful despite a better solution being available. Literature on this close type of relationship is sparse, mostly because information on such internal processes is generally regarded as competitive. The case investigated was the DebTech division of De Beers, and their experience with products that they design and manufacture for the global diamond mining industry. Product developer and customer data from applicable projects was analysed, and interviews and observations were conducted. The results indicate that familiarity with the product technology favourably influences perceptions of newness, safety, and the ease of integration of a product. Familiarity increases customers&apos; propensity to recommend and purchase new-technology products.
Die invloed is ondersoek van vertroudheid met nuwe tegnologie op nywerheidskliënte se aankoopbesluite van diskontinue nywerheidsprodukte. Dit is gedoen in die konteks waar die verskaffer- en kliëntorganisasies entiteite in dieselfde maatskappy is. Selfs in hierdie gunstige opset is ervaar dat kontinue nywerheidsprodukte meer verkoop, al is &apos;n beter oplossing beskikbaar. Literatuur oor hierdie tipe verhouding is skaars, hoofsaaklik omdat inligting oor sodanige interne prosesse normaalweg as mededingend beskou word. Die geval is ondersoek van die DebTech-afdeling van De Beers se ervaring met produkte wat dit vir die internasionale diamantmynbedryf ontwerp en vervaardig. Produkontwikkelaar- en kliëntdata van toepaslike projekte is ontleed, aangevul met onderhoude en waarnemings. Die resultate toon dat kliënte se vertroudheid met die produktegnologie hulle persepsies van nuutheid, veiligheid, en integreerbaarheid van nuwe-tegnologieprodukte gunstig beïnvloed. Tegnologievertroudheid verhoog hulle geneigdheid om nuwe-tegnologieprodukte aan te beveel en te koop.
A longitudinal study of the indicators and factors for successful Six Sigma deployment in the South African mining industry
South African Journal of Industrial Engineering 24, pp 167 –191 (2013)
The Six Sigma deployment methodology is known for its results in operational excellence associated with improved business practices. Organisations worldwide have shown significantly reduced costs and increased profits when successfully deploying Six Sigma. This paper reports a longitudinal study of a set of indicators and success factors for Six Sigma deployment, using Lonmin PLC, a mining company in South Africa, as a case. The results suggest a shift of indicators from heartfelt personal involvement in 2006 to a mechanistic performance-based culture in 2010. Practical recommendations are made regarding the nine success factor components to be included during Six Sigma deployment.
Die ontplooiing van die sogenaamde "Six Sigma"-metode het &apos;n bydrae gemaak tot bedryfsuitnemendheid deur verbeterde sakepraktyke aan te moedig in die bereiking van laer koste en verbeterde wins. Verslag word gedoen oor &apos;n versameling van sake-indikatore en suksesfaktore in &apos;n gevallestudie van &apos;n Suid-Afrikaanse mynmaatskappy. Voorstelle word gemaak oor die aanwending van nege suksesfaktore wanneer die "Six Sigma"-metode gebruik word.
T. Leonard and
South African Journal of Industrial Engineering 24, pp 192 –206 (2013)