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South African Journal of Industrial Engineering 18 (2007)
After eight years and 159 articles on 2,432 pages in 16 issues of the South African Journal of Industrial Engineering, it is time for me to say goodbye as editor.
Confronting the inevitable : ISO 14001 implementation and the Durban automotive cluster
A. Turner and
South African Journal of Industrial Engineering 18, pp 1 –19 (2007)
The aim of the article is to explore the complexities of the ISO 14001 implementation process, with the objective of identifying the barriers to its implementation, the factors that influence these barriers, and finding possible solutions to address these barriers. The theoretical basis of ISO 14001, the implementation process, and its strategic implications were established by reviewing previous research. Based on this theoretical review, a self-administered questionnaire was designed to serve as a measuring instrument for the empirical research conducted among members of the Durban Automotive Cluster (DAC). The specific objectives of the empirical study were: to determine the reasons for seeking ISO 14001 certification, to determine the perceived and experienced barriers to its implementation, and to investigate the strategic implications of an Environmental Management System (EMS) such as ISO 14001. Finally, the findings, recommendations, caveats, and suggestions for further research are summarised.
Die oogmerk van hierdie artikel is om die kompleksiteit van die ISO 14001 implementeringsproses te ondersoek met die doel om die hindernisse wat implementering belemmer en die faktore wat hierdie hindernisse beïnvloed vas te stel, en moontlike oplossings te vind. Die teoretiese grondslag van ISO 14001, die implementeringsproses, en die strategiese implikasies is op &apos;n oorsig van bestaande navorsing gebaseer. Gegrond op hierdie teoretiese oorsig is &apos;n selfgeadministreerde vraelys opgestel om as metingsinstrument te dien vir die empiriese navorsing wat onder lede van die "Durban Automotive Cluster (DAC)" uitgevoer is. Die spesifieke doelstellings van die empiriese studie was: om die redes waarom ISO 14001 sertifisering nagestreef is te bepaal; om die persepsies van en werklike hindernisse ten opsigte van implementering te bepaal; en om die strategiese implikasies van &apos;n Omgewingsbestuursisteem soos ISO 14001 te ondersoek. Die bevindings, aanbevelings, tekortkominge, en voorstelle vir verdere navorsing word ten slotte in die artikel saamgevat.
Environmental management systems in the automotive supply chain in South Africa : a pilot study
A.C. Brent and
South African Journal of Industrial Engineering 18, pp 21 –34 (2007)
Automobile Original Equipment Manufacturers (OEMs) have implemented formal Environmental Management Systems (EMSs) globally that require the OEMs to consider the environmental performance and potential liabilities in the supply chain. However, in South Africa, OEMs typically experience resistance from suppliers to focus on environmental issues, compliance with regulations, and OEM requirements. Although the responses from many OEMs have been an attempt to enforce the formal EMS certification and accreditation of suppliers, a case study reveals that such certification and accreditation does not necessarily imply good environmental performance, nor indeed environmental compliance with the national legislation. Apart from general environmental management and compliance information, basic cleaner production process parameters, i.e. water and energy usage, and waste generated, were used to compare the environmental performances of different sized suppliers, with and without formal EMSs, and with variance of financial dependency on an OEM. In order to improve the environmental performance of the entire supply chain, a conceptual model is introduced, which is currently under investigation in the automotive sector of South Africa.
Oorspronklike Toerusting Vervaardigers (OTVs) in die motorbedryf het internasionaal formele Omgewingsbestuursisteme (OBS) geïmplementeer wat vereis dat die omgewingsprestasie en potensiële aanspreeklikhede van die verskaffingsketting in ag geneem moet word. Nieteenstaande ondervind OTVs in Suid-Afrika weerstand van verskaffers wanneer gefokus word op omgewingsaspekte, voldoening aan regulasies en OTV-verwagtinge. Alhoewel die meerderheid OTVs formele OBS akkreditering probeer afdwing, toon &apos;n gevallestudie dat dit nie noodwendig omgewingsprestasie, en voldoening aan nasionale omgewingswetgewing, impliseer nie. Afgesien van algemene omgewingsbestuur en regsvoldoening, was produksieprosesparameters, soos water- en energieverbruik, en afvalgenerering, gebruik om die omgewingsprestasie van verskillende verskaffers, met of sonder OBS, en met variasie in finansiële afhanklikheid van &apos;n OTV, te vergelyk. Om die omgewingsprestasie van die verskaffingsketting te verbeter, word &apos;n konsepsuele model wat tans in the motorvervaardigingsektor van Suid-Afrika ondersoek word, voorgestel.
A fuzzy extent analysis method for vendor selection in supply chain : a case study from the automotive industry
South African Journal of Industrial Engineering 18, pp 35 –55 (2007)
The analytic hierarchy process (AHP) of Saaty (1980) is a popular method for solving multi-criteria decision problems involving qualitative data, and has been applied to the vendor selection process (Nydick and Hill, 1992; Barbarosoglu and Yazgac, 1997; Narasimhan, 1983; and Masella and Rangone, 2000). AHP is often criticized for its inability to handle the inherent uncertainty and imprecision of the pairwise comparison process. This paper focuses on addressing uncertainty issues in the process of vendor selection by using a Fuzzy Extent Analysis method. The applicability of the proposed Fuzzy Extent Analysis method for vendor selection is tested in Auto Exhaust System Ltd, Gurgaon, India. A study of the Fuzzy Extent Analysis Method is also provided in this paper by experimenting with sensitivity analysis. The result shows that the Fuzzy Extent Analysis Method for vendor selection is simple and comprehensive in concept, efficient in computation, and robust in modeling human evaluation processes for vendor selection.
Die analitiese hiërargieproses (AHP) van Saaty (1980) bied &apos;n populêre metode vir die oplossing van veeldoelige kwalitatiewe besluitvormingsprobleme. Dit is reeds toegepas op gevalle van leweransierseleksie (Nydick en Hill, 1992; Barbarosoglu en Yazgac, 1997; Narasimhan, 1983; en Masella en Rangone, 2000). Die AHP-metode word dikwels gekritiseer omdat dit nie inherente onsekerhede en onakkuraatheid van paargewyse vergelykings kan hanteer nie. Die artikel omseil die kritiek deur gebruik te maak van &apos;n Wasigheidsleermetode. Die metode word beproef vir &apos;n leweransierseleksievraagstuk by Auto Exhaust Systems Bpk., Gurgaon, Indië. Daar word ook geëksperimenteer met sensitiwiteitsanalise wat bewys lewer van die doeltreffendheid van die metode van ontleding.
Managing centrifugal pump reliability in the context of total cost of ownership
J. Van der Poel and
C.C. Van Waveren
South African Journal of Industrial Engineering 18, pp 57 –70 (2007)
The management of a population of centrifugal pumps in the petrochemical industry can be daunting. A popular method for strategically optimizing the maintenance and operation of these centrifugal pumps is to measure the reliability of the whole pump population in terms of Mean-Time-Between-Failures (MTBF). Too often MTBF improvement becomes the focus rather than a means of supporting the actual goal, namely Total Cost of Ownership (TCO) reduction. An increase in MTBF is intuitively associated with a reduction of TCO, but this is not necessarily true. This study proposes that the &apos;MTBF vs time&apos; and &apos;TCO vs MTBF&apos; curves are characteristics of a specific industrial plant. A tool for approximating the optimum TCO vs MTBF for a plant is introduced, and a qualitative framework for managing pump reliability in the TCO context is proposed.
Die bestuur van &apos;n sentrifugale pomppopulasie in die petrochemiese bedryf kan oorweldigend wees. &apos;n Populêre metode om die instandhouding en bedryf van hierdie sentrifugale pompe op &apos;n strategiese vlak te optimiseer, is om die betroubaarheid van die pomppopulasie in geheel, in terme van Gemiddelde-Tyd- Tussen-Falings (GTTF), te meet. Die fokus word te veel op die verbetering van die GTTF geplaas en nie op die eintlike doel, naamlik die vermindering van Totale Koste van Eienaarskap (TKE) nie. &apos;n Verbetering in die GTTF word intuïtief geassosieer met &apos;n vermindering van TKE, maar dit is nie noodwendig waar nie. Hierdie studie stel voor dat die &apos;GTTF vs Tyd&apos;-kurwe en &apos;TKE vs GTTF&apos;-kurwe kenmerkend is van &apos;n spesifieke industriële aanleg. &apos;n Instrument om die benaderde optimum TKE vs GTTF vir &apos;n aanleg te bepaal, asook &apos;n kwalitatiewe raamwerk om pomp betroubaarheid in die TKE konteks te bestuur, word voorgestel.
Systems with extended availability and switchover delays
M.A. Shahul Hameed,
L. Prathaban and
South African Journal of Industrial Engineering 18, pp 71 –92 (2007)
A system with extended availability and switchover delays with a single repair facility is considered, with a random extended available period having a switching delay from online failure to the repair of the facility. Identifying suitable regeneration points, several operating characteristics, such as the moment generating function of the total uptime, mean, and mean square number of various events, are obtained, apart from reliability and availability functions.
&apos;n Stelsel met verlengde beskikbaarheid, oorskakelvertraging met &apos;n enkele herstelfasiliteit en &apos;n toevalverlengde beskikbaarheidsperiode met oorskakeling vanaf intydse mislukking tot herstel, word behandel. Deur geskikte regenerasiepunte te identifiseer, kan verskeie bedryfseienskappe (benewens betroubaarheid en beskikbaarheid) soos &apos;n momentgenerende funksie vir totale beskikbare tyd, gemiddelde en gemiddelde kwadraatwaardes vir verskeie gebeurtenisse, bepaal word.
A software reliability growth model for vital quality metrics
G. Gopal and
South African Journal of Industrial Engineering 18, pp 93 –108 (2007)
A Non-Homogenous Poisson Process (NHPP) model whose failure intensity function has the same mathematical form as that of a generalized exponential function was proposed for application as a Software Reliability Growth Model (SRGM). However, in order to facilitate collecting quality metrics pertaining to the degree of imperfect or efficient debugging phenomena and the number of faults left in the software, in this paper the authors propose an extension to the above SRGM. This SRGM enables adequate goodness of fit statistic and predictive validity, even when the software projects witness learning phenomenon of the testing team, either imperfect or perfect or efficient software debugging phenomenon, as well as wide fluctuations in time between failures - either occurring alone or in combinations thereof.
&apos;n Nie-homogene Poissonproses (NHPP) waarvan die mislukkingsdigtheidsfunksie soortgelyk is aan &apos;n algemene eksponensiële funksie word voorgehou as &apos;n programmatuur-betroubaarheidsgroeimodel (PBGM). Die model lewer toereikende passingsgoedheid en voorspellingsgeldigheid onder uiteenlopende leereienskappe van toetsers, swak of goeie ontfouting van programmatuur, en groot verskille tussen waardes van tyd tussen mislukkings. Die outeurs stel ook voor dat die goedheid van ontfoutingsaksies gemeet word met behulp van &apos;n uitbreiding van die PBGM-model.
Six Sigma : a literature review
South African Journal of Industrial Engineering 18, pp 109 –129 (2007)
Despite stiff international competition in the global market, world-class manufacturers are increasing their market share and profits through low-cost production, waste reduction in manufacturing, production of high quality products, and exceptional customer service. Six Sigma has been successfully implemented in this regard. In this paper, a selected survey of Six Sigma literature is presented to illustrate the wide scope of the application of the concept. This could be of immense benefit to organizations&apos; top management who need to understand the critical variables and factors for the successful implementation of Six Sigma programmes, leading to substantial, sustainable long-term improvement in performance results, value for money, and effort. The paper presents motivated pointers - substantiated as far as possible by data and evidence - to key success factors, variables, and their interrelationships.
Sterk internasionale mededinging ten spyt verhoog wêreldklasvervaardigers hul markaandeel en winste via laekosteproduksie, skrootvermindering, die produksie van gehalteprodukte en die lewering van primadiens aan klante. Ses Sigma is in hierdie verband as gereedskap suksesvol geïmplimenteer. Die artikel behandel &apos;n gekeurde oorsig van Ses Sigmaliteratuur om sodoende die toepassingsveldwyde van die konsep te illustreer. Die artikel is nuttig vir organisasiebestuurders uit die oogpunt van veranderlikes en suksesfaktore wat deur die Ses Sigmametode tot substansiële en volhoubare langtermyn verbeterings van &apos;n onderneming kan lei.
K. Thaga and
South African Journal of Industrial Engineering 18, pp 131 –152 (2007)
This paper proposes an exponentially weighted moving average (EWMA) control chart that is capable of detecting changes in both process mean and standard deviation for autocorrelated data (referred to as the Maximum Exponentially Weighted Moving Average Chart for Autocorrelated Process, or MEWMAP chart). This chart is based on fitting a time series model to the data, and then calculating the residuals. The observations are represented as a first-order autoregressive process plus a random error term. The Average Run Lengths (ARLs) for fixed decision intervals and reference values (h, k) are calculated. The proposed chart is compared with the Max-CUSUM chart for autocorrelated data proposed by Thaga (2003). Comparisons are based on the out-of-control ARLs. The MEWMAP chart detects moderate to large shifts in the mean and / or standard deviation at both low and high levels of autocorrelations more quickly than the Max-CUSUM chart for autocorrelated processes.
Die navorsing stel voor dat &apos;n eksponensiaal geweegde bewegende gemiddelde kontrolekaart gebruik word om verandering van prosesgemiddelde en - standaardafwyking van outogekorreleerde data te bepaal. Die kontrolekaart word gedryf deur passing van &apos;n tydreeks as datamodel met bepaling van residuwaardes. Met hierdie gegewens as vertrekpunt word gemiddelde looplengtes vir vaste besluitintervalle en verwysingwaardes (h, k) bereken. Die kontrolekaart bepaal matige en groot verskuiwings van waardes vir hoë en lae outokorrelasiewaardes heel snel.
Using a simulation model to determine the optimum number of pilots in an air force
M. Albertyn and
South African Journal of Industrial Engineering 18, pp 153 –168 (2007)
The key objective is to present a simulation model to determine the optimum number of pilots in an air force. Background information about the simulation project, and a cursory description of the system under consideration, are provided. The Simul8 simulation software package, the basic concepts of the simulation model, the determination of adequate samples sizes, and simulation model verification and validation are discussed. Generic examples of typical results are shown, and conclusions about the simulation project are presented.
Die hoofdoelwit is om &apos;n simulasiemodel voor te hou wat gebruik word om die optimale aantal vlieëniers in &apos;n lugmag te bepaal. Agtergrond inligting oor die simulasieprojek en &apos;n oppervlakkige beskrywing van die stelsel onder beskouing word voorsien. Die Simul8 simulasiesagtewarepakket, die basiese konsepte van die simulasiemodel, die vasstelling van voldoende monstergroottes, en simulasiemodel verifikasie en validering word bespreek. Generiese voorbeelde van tipiese resultate word getoon, en gevolgtrekkings oor die simulasieprojek word voorgehou.
J.K. Visser and
South African Journal of Industrial Engineering 18, pp 169 –185 (2007)
The maintenance of some sophisticated and complex equipment - for example, diagnostic equipment used in hospitals - is frequently outsourced to the original equipment supplier or another maintenance service provider. Companies that own such assets can either enter into a service agreement, or they can use service providers on a call-out basis. A fundamental problem for the provider of maintenance services is to determine the optimum number of maintenance technicians or artisans. An investigation was done for a service company that provides planned and breakdown maintenance services to hospitals and clinics that use specialised medical imaging equipment. Data on the duration of maintenance tasks and traveling costs were used to obtain an input distribution for a simulation model. The model that was developed can now be used to determine the number of technicians that would optimise the service company&apos;s profit. This paper discusses the features of the simulation model, as well as some results obtained with the basic simulation model.
Die instandhouding van sommige gesofistikeerde en komplekse toerusting, soos byvoorbeeld diagnostiese toerusting wat in hospitale gebruik word, word dikwels uitgekontrakteer na die oorspronklike vervaardigers van die toerusting. Ondernemings wat sulke toerusting besit kan dan &apos;n diensleweringskontrak met die diensverskaffer aangaan, of gebruik maak van &apos;n uitroepstelsel. &apos;n Fundamentale probleem vir die diensverskaffer is om die optimum aantal tegnici te bepaal. &apos;n Ondersoek is gedoen vir &apos;n tipiese diensverskaffer wat beplande sowel as onbeplande instandhouding doen vir hospitale en klinieke wat gesofistikeerde optiese toerusting bedryf. Data vir die tydsduur van take sowel as reistyd is gebruik om insetverdelings te verkry vir die ontwikkeling van &apos;n simulasiemodel. Die model wat ontwikkel is kan gebruik word om die aantal tegnici te bepaal wat die wins vir die diensmaatskappy sal optimeer. Hierdie artikel bespreek die eienskappe van die simulasiemodel wat ontwikkel is, sowel as van die resultate wat met die basiese simulasiemodel verkry is.
N.D. Du Preez and
South African Journal of Industrial Engineering 18, pp 187 –201 (2007)
This paper describes the role and use of enterprise engineering concepts as a formal approach to the deployment of sustainable networks of small businesses in South Africa. Small, medium and micro enterprises (SMMEs) operating in the informal South African economy struggle to survive for various reasons. A business framework is suggested that supports informal SMMEs through their initial stages of operation, and by doing so, improves sustainable growth and employment opportunities. This implies integration of informal business activities with the formal economy. The business framework is constructed using the Zachman Enterprise Reference Architecture, and is benchmarked by a small-scale fish farming project case study to validate the research hypothesis.
Hierdie artikel beskryf die toepassing van bedryfsingenieurswesebeginsels as &apos;n formele benadering tot die ontwikkeling van volhoubare netwerke van klein ondernemings in Suid-Afrika. Verskeie faktore dra by tot die sukkelende voortbestaan van "SMMEs" in die informele ekonomie van die land. As moontlike oplossing vir hierdie probleem word &apos;n besigheidsraamwerk voorgestel wat informele "SMMEs" gedurende hul aanvangsfase ondersteun en daardeur volhoubare groei en werkskeppingsgeleenthede verbeter. Realisering van hierdie besigheidsraamwerk impliseer integrasie-aktiwiteite tussen die informele en formele ekonomieë. Die besigheidsraamwerk is ontwikkel met behulp van Zachman se Besigheidsverwysingsargitektuur. &apos;n Visboerderyprojek dien as gevallestudie vir validasie van hierdie navorsingshipotese.
Utilizing formal innovation models to support and guide industry innovation projects
H. Van Zyl,
South African Journal of Industrial Engineering 18, pp 203 –219 (2007)
The high failure rate of innovation projects indicates that many companies are not getting the full benefit from their innovation projects , . A research project was carried out during 2005 that explored and compared the existing formal models for supporting innovation, in order to address the identified problem. It proposed guidelines for improving and refining innovation projects. A case study that focused on the front-end of product innovation in the wine industry and the applicability of the formal W-model  to innovation activities was used to evaluate how formal innovation models can indeed effectively support industry innovation projects. The innovation life cycle was used to categorize a number of innovation frameworks for product, process, and enterprise innovation. Further research should focus on extending the case study to other industries, such as the automotive sector.
Die groot aantal onsuksesvolle innovasie projekte dui daarop dat maatskappye nie die volle voordele uit hul innovasie projekte kry nie , . &apos;n Navorsingsprojek is gedurende 2005 uitgevoer om bestaande formele innovasie modelle te evalueer, ondersoek, en vergelyk, met die doel om bogenoemde probleem aan te spreek en riglyne voor te stel wat innovasie sal bevorder en verfyn. &apos;n Gevallestudie, wat fokus op produkinnovasie in die wyn-industrie, is uitgevoer om die toepaslikheid en effektiewe ondersteuning van die formele W-model  op spesifieke innovasie aktiwiteite te evalueer. Die innovasie-lewensiklus is ook gebruik om &apos;n aantal innovasie-raamwerke te kategoriseer in afdelings vir produk-, onderneming- en proses-innovasie. Toekomstige navorsing behoort te fokus op &apos;n uitbreiding van die gevallestudie na ander industrië soos die motorindustrie.
S.S. Grobbelaar and
South African Journal of Industrial Engineering 18, pp 221 –230 (2007)
There is some concern about the future ability of South Africa&apos;s Research and Development (R&D) system to produce R&D output. This paper documents a Delphi study that was conducted in order to gain insight into the opinion of experts regarding the most pressing issues facing the South African R&D system in the next 20 years. Two main themes emerge from the study. First, experts foresee poor prospects for the retention and rejuvenation of researchers in the system. The second theme is the poor prospects for sufficient funding for R&D in the next 20 years. In general, there was a high level of agreement that the issues were critical. The exception was the respondents&apos; opinion on the negative effect current Black Economic Empowerment policies might have on quality and R&D capacity in the private sector.
Daar bestaan &apos;n mate van kommer oor die toekomstige vermoë van Suid-Afrika se Navorsing en Ontwikkeling(N&O)-stelsel om N&O-uitsette te lewer. In hierdie verslag word &apos;n Delphistudie gedokumenteer wat uitgevoer is om kenners se opinies in te win rakende die mees dringende sake wat die Suid-Afrikaanse N&O-stelsel in die volgende 20 jaar in die gesig staar. Twee temas kom na vore in die navorsing. In die eerste plek, voorsien kenners swak vooruitsigte vir die behoud en vernuwing van personeel van die stelsel. In die tweede plek, word swak vooruitsigte in terme van voldoende befondsing vir N&O oor die volgende 20 jaar voorsien. Oor die algemeen is &apos;n hoë mate van samestemming ten opsigte van die kritikaliteit van die aangeleenthede gevind. Die uitsondering was die respondente se opinie van die negatiewe effek wat huidige Swart Ekonomiese Bemagtigingsbeleid mag hê op die kwaliteit en vermoëns van N&O in die privaatsektor.