Scielo RSS <![CDATA[South African Journal of Industrial Engineering]]> http://www.scielo.org.za/rss.php?pid=2224-789020190001&lang=en vol. 30 num. 1 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=S2224-78902019000100001&lng=en&nrm=iso&tlng=en <![CDATA[<b>Design and implementation of deadlock control for automated manufacturing systems</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100002&lng=en&nrm=iso&tlng=en Petri nets are robust mathematical tools for the modelling, handling, and control of deadlock problems in automated manufacturing systems (AMSs). Several methods have been proposed to prevent deadlocks in AMSs. However, it is important to convert the controlled system represented by Petri nets into the program of a programmable logic controller (PLC) for the implementation of automation tasks. This study proposes a methodology based on Petri nets for deadlock prevention, and generates PLC codes for an AMS. In the suggested methodology, a Petri net model of an uncontrolled system is built, and the controlled Petri net model is developed using a deadlock-prevention method. The controlled Petri net model is then transformed into an automation-controlled Petri net model, which is further converted into a controlled token-passing logic model. The controlled token-passing logic model is utilised to generate the ladder diagrams for the AMS under consideration. The proposed methodology was tested using a real-world AMS at King Saud University labs. It provides an effective method for PLC implementation from a controlled system model represented by Petri nets.<hr/>Petri-nette is robuuste wiskundige instrumente wat gebruik word om dooiepunt probleme in geoutomatiseerde vervaardigingstelsels (AMSe) te modelleer, hanteer en te beheer. Verskeie metodes is al voorgestel om dooiepunte in AMSe te verhoed, maar dit is belangrik om die beheerde stelsel deur die Petri-nette voorgestel om te skakel na die rekenaarkode van 'n programmeerbare logiese beheerder (PLC) sodat dit geïmplementeer kan word. 'n Metodologie gegrond op Petri-nette vir dooiepunt voorkoming word voorgehou en genereer PLC rekenaarkode vir AMSe. In die voorgestelde metodologie word n Petri-netmodel van n onbeheerde stelsel geskep en die beheerde Petri-netmodel is dan ontwikkel met die dooiepuntvoorkomingsmetode. Die beheerde Petri-net model word dan getransformeer tot 'n outomasiebeheerde Petri-netmodel wat dan verder omskep word in n beheerde kenteken-aanstuur logiese model. Hierdie model word dan gebruik om leerdiagramme vir die AMS te genereer. Dié metodologie is getoets in 'n reële wêreld AMS by die King Saudi Universiteit se laboratoriums. Dit verskaf n effektiewe metode vir PLC implementering van n beheerde stelsel wat deur Petri-nette voorgestel word. <![CDATA[<b>Diagnostic assessment of service delivery health in South Africa: a systematic literature review</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100003&lng=en&nrm=iso&tlng=en Access to cost-effective, high-quality and speedy public services is a legitimate requirement and expectation of all South Africans. However, despite massive increases in successive budgets and grants to the public sector, the economy continues to witness frequent unrest that is typically tagged as being about 'service delivery'. To deal effectively with this conundrum, an evidence-driven, goal-oriented diagnosis of the health of service delivery in South Africa is required. This is even more important as service delivery deficits and backlogs have continued to grow and widen since democratisation. It is therefore pertinent that a diagnostic tool with a sound and rigid theoretical foundation, and rigorously evaluated against key performance metrics, be developed as part of efforts to close service delivery gaps. This paper explores the necessary criteria for a diagnostic tool to contribute effectively in closing service delivery gaps in South Africa.<hr/>Toegang tot koste effektiewe, hoë gehalte en vinnige publieke dienste is 'n geldige vereiste en 'n verwagting van alle Suid-Afrikaners. Ten spyte van massiewe toenames in opeenvolgende begrotings en toelaes aan die publieke sektor, word die ekonomie steeds blootgestel aan gereëlde onrus wat tipies aan swak dienslewering toegeskryf word. Om effektief met hierdie strikvraag te werk te gaan is 'n doelgerigte diagnose van die toestand van dienslewering in Suid-Afrika benodig. Dit is selfs belangriker soos dienslewering tekortkominge en agterstande toegeneem en versprei het sedert demokrasie in Suid-Afrika. Dit is daarom belangrik dat 'n diagnostiese instrument met 'n stewige teoretiese fondament ontwikkel en deeglik getoets word teen sleutel vertonings-maatstawwe in 'n poging om dienslewering tekortkominge aan te spreek. Hierdie artikel ondersoek die nodige kriteria vir so n diagnostiese instrument om sodoende noemenswaardig by te dra tot die verbetering van dienslewering in Suid-Afrika. <![CDATA[<b>A learning curve theory perspective on projects. Ranking the key determinants to improve project efficiency</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100004&lng=en&nrm=iso&tlng=en The desire to gain knowledge about the quality and timing of construction projects delivered to clients has become an increased focus point in the field of construction management. Clients have expectations that are often based on their assumptions about the validity of making the learning curve theory applicable to construction projects. This research aims to determine what criteria need to be met for the learning curve theory to have some validity for construction projects. The results from the questionnaire survey, completed by professionals from the construction industry, show that several concepts were found to be of importance: project specifications, design, scope, budget, site management, planning, monitoring and controlling, and quality. If these concepts correspond between two projects, the chance of successfully applying the learning curve theory increases. Practical recommendations are made that highlight the concepts identified as critical for the successful application of the learning curve theory to construction projects, and that can be used by clients and contractors as a basis for negotiating project schedules.<hr/>As deel van die evolusie in konstruksiebestuur het kennis van projekkwaliteit asook die tydsduur van konstruksieprojekte 'n groter noodsaaklikheid geword. Kliënte het verwagtinge wat dikwels gebaseer word op persoonlike aannames rondom die geldigheid van die leerkurweteorie en die toepaslikheid daarvan op konstruksieprojekte. Die doel van hierdie navorsing is om die projekkriteria te bepaal wat in plek moet wees om die geldigheid van die leerkurweteorie op konstruksieprojekte te bevorder. Die uitslag van die opnamevraelys, wat deur professionele persone in die konstruksiebedryf voltooi is, het getoon dat daar verskeie kriteria van belang is, naamlik: die projekspesifikasie, die ontwerp en omvang van die projek, die begroting, die bestuur van die konstruksiewerf, die beplanning, monitering en kontrole, asook die kwaliteitverwagtinge van die projek. Indien meerdere van hierdie kriteria tussen twee projekte ooreenstem, verhoog dit die kans dat die leerkurweteorie suksesvol van een projek na 'n ander toegepas kan word. Ter afsluiting word praktiese aanbevelings gemaak wat die belangrike kriteria uitlig wat nodig is vir die suksesvolle toepassing van die leerkurweteorie op konstruksieprojekte. Hierdie aanbevelings kan deur kliente en kontrakteurs gebruik word as n basis tydens die onderhandeling van projekskedules vir opkomende en soortgelyke projekte. <![CDATA[<b>Development of a software-based monitoring and information system for industrial telemetry applications</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100005&lng=en&nrm=iso&tlng=en Industry stands to benefit from adopting Internet of Things (IoT) practices. However, reliability and quality of service are of the utmost importance. Challenges such as intermittent connectivity in wide-area wireless communications can hamper the adoption and efficiency of IoT principles in industry. The aim of this paper, therefore, is to propose a new system that actively monitors the status of a wide-area wireless communications network to improve quality of service and ensure reliability. The new monitoring system was implemented on a telemetry system that is used by multiple industrial facilities in the Republic of South Africa. Successful monitoring of 80 remote end-points with more than one thousand individual industrial components was achieved, with communication failures or anomalies being detected immediately. In addition to the immediate detection of communication failures, the average connection uplink time was increased by more than 25 per cent.<hr/>Die industriële sektor kan baat by die integrasie van 'Internet of Things' (IoT) toepassings. Betroubaarheid en gehalte van diens is egter belangrike faktore wat in ag geneem moet word. Huidige uitdagings soos onstabiele konnektiwiteit in koordlose netwerke kan negatiewe gevolge hê in industriële toepassings. Die doel van hierdie studie is om 'n unieke stelsel voor te stel wat in staat is om koordlose kommunikasie netwerke met 'n groot omvang te monitor, met die doel om die gehalte van diens en betroubaarheid van hierdie netwerke te verbeter. Die stelsel was prakties ontwikkel en geïntegreer met 'n bestaande netwerk wat verskeie industriële fasiliteite in die Republiek van Suid-Afrika koordloos verbind. Die stelsel was in staat om tagtig afgeleë industriële eindpunte te monitor. Meer as eenduisend individuele industriële komponente word direk geaffekteer, en konneksie probleme tussen industriële aanlegte was onmiddelik opgespoor. Algehele konnektiwiteit was verbeter met meer as 25 persent. <![CDATA[<b>Multiplicative LMDI approach to South Africa's industrial energy consumption</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100006&lng=en&nrm=iso&tlng=en As a developing country, South Africa's manufacturing sectors have led to the country's present industrialisation. Where industrialisation occurs, energy plays a pivotal role. This study, therefore, focuses on analysing and understanding the contributing factors responsible for the energy consumed in South Africa's manufacturing sectors. The period under investigation is from 1970 to 2016. Two different modes of understanding the factors responsible for energy consumption are structural decomposition analysis (SDA) and index decomposition analysis (IDA). The latter was preferred for this study. The logarithmic mean divisia index (LMDI) was adapted for the analysis. The energy consumed by the manufacturing sector is decomposed into the activity, structure, and intensity effects. Results show that both intensity effects and structure effects contributed to the country's energy efficiency by 3.10 per cent and 1.73 per cent. On the other hand, activity effects contributed to the rise of industrial energy consumption by 8.04 per cent. The empirical findings of this study support initiatives in the form of policies to concentrate more on the industrial activity effects to complement energy efficiency strategies.<hr/>Suid-Afrika se vervaardigingsindustrie het gelei tot die huidige vlak van industrialisering. Energie speel 'n belangrike rol in so 'n geval. Hierdie studie fokus daarop om die bydraende faktore wat verantwoordelik is vir die energieverbruik in die Suid-Afrikaanse vervaardigingsindustrie te ontleed en te verstaan. Die tydperk van 1970 tot 2016 word by hierdie studie ingesluit. Twee verskillende metodes om die bydraende faktore te verstaan is strukturele ontbindingsanalise en indeks ontbindingsanalise. Die laasgenoemde is vir hierdie studie ingespan. Die logaritmiese gemiddelde verdelingsindeks (LMDI) is aangepas vir die analise. Die energie-verbruik van die vervaardigingsektor is opgedeel in die aktiwiteit-, struktuur- en intensiteit-effekte. Resultate toon dat beide die intensiteit- en die struktuur-effekte bydra tot die land se energie doeltreffendheid deur onderskeidelik 3.10 en 1.73 persent. Daarteenoor het aktiwiteit-effekte bygedra tot 'n 8.04 persent toename in industriële energieverbruik. Die empiriese bevindings in hierdie studie ondersteun beleidsinisiatiewe wat fokus op industriële aktiwiteite om sodoende energie doeltreffendheid aan te vul. <![CDATA[<b>Single-machine scheduling of indivisible multi-operation jobs</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100007&lng=en&nrm=iso&tlng=en This paper considers a single-machine scheduling problem of multi-operation jobs where each job consists of several operations processed contiguously, rather than being intermingled with the operations of different jobs. That is, the jobs are indivisible. A sequence-independent setup is required if the machine switches from one operation to another. However, no setup is necessary before the first operation of a job if this first operation is the same as the last operation of the immediately previous job. A job is complete when all of its operations have been processed. We investigate the problem for two cases. Makespan, which is the time needed to complete all jobs, is minimised in the first case; whereas the total completion time, which is the sum of the job completion times, is minimised in the second case. We show that the makespan problem is solvable in polynomial time. For the problem of minimising total completion time, we develop a mixed integer linear programming (MILP) model, which is capable of solving small and medium-sized problem instances optimally, and obtain a very small gap between the solution found and the best possible solution for the unsolved large-sized problem instances.<hr/>Hierdie artikel ondersoek 'n enkel-masjien skeduleringsprobleem van meervoudige operasie take waar elke taak uit verskeie operasies bestaan wat kontinu verwerk word eerder as om gemeng te wees met die operasies van ander take. Die take is dus onverdeelbaar. 'n Volgorde-onafhanklike opstelling word vereis as die masjien wissel van operasie na 'n ander. Geen opstelling is egter nodig voor die eerste operasie van 'n taak indien die eerste operasie van die nuwe taak dieselfde is as die vorige taak se laaste operasie nie. Die tyd wat dit neem om elkeen van die take te voltooi is eerstens geminimeer. Daarna is die totale voltooi tyd (die som van al die taak voltooi tye) geminimeer. Daar word gewys dat die tyd wat dit neem om elke taak te voltooi oplosbaar is in polinome tyd. Om die totale voltooi tyd te minimeer is 'n gemengde heelgetal lineêre programmeringmodel ontwikkel wat daartoe in staat is om klein- en mediumgrootte probleme optimaal op te los. Die model behaal ook 'n baie klein verskil tussen die geïdentifiseerde oplossing en die beste moontlike oplossing vir groot probleemgevalle. <![CDATA[<b>Analysis of the use of space and module-configured packaging to improve fruit export mass in a refrigerated container</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100008&lng=en&nrm=iso&tlng=en The South African fruit export industry is a key contributor to the country's economy, and must be managed efficiently to that ensure its vital role is maintained. Significant increases in reefer freight rates have placed substantial pressure on the fruit export industry to find new and innovative ways of improving the space / volume use of fruit in these reefer containers. Improvements must adhere to key constraints to ensure that fruit quality and shelf life are not compromised. This paper analyses the current potential for increasing the mass of stone and pome fruit that is exported in reefer containers. The study indicates that pome fruit has the greatest opportunity for improvement, whereas stone fruit has less room for improving the use of space / volume. Proposed improvement methods are: optimal packing arrangements of fruit; improved packaging and pallet dimensions (special pallet sizes); improved stacking arrangements of cartons on pallets and pallets in reefers; and lastly, the use of slip sheets instead of pallets.<hr/>Die Suid-Afrikaanse vrugte uitvoer industrie is 'n belangrike bydraer tot die land se ekonomie, en moet doeltreffend bestuur word om te verseker dat hierdie rol volhou word. Beduidende toenames in koelhouer vragkostes het aansienlike druk op die vrugte uitvoer industrie geplaas om nuwe en innoverende maniere te vind om die spasie / volume benutting binne die koelhouers te verbeter. Verbeteringe moet voldoen aan belangrike beperkings om te verseker dat die kwaliteit en raklewe van vrugte nie benadeel word nie. Hierdie studie ontleed die potensiaal om die uitvoer massa van steen- en kernvrugte in verkoelde houers te verhoog. Die studie dui aan dat kernvrugte die grootste geleentheid bied vir verbetering, terwyl met steenvrugte daar minder potensiaal is om spasie / volume benutting te verbeter. Die voorgestelde verbeterings-metodes is soos volg: optimale verpakkingsreëlings van vrugte; verbeterde verpakking en palletafmetings (spesiale pallet-groottes); verbeterde stapelreëlings van kartonne op palette en palette in koelkashouers; en laastens, die gebruik van 'slip sheets' in plaas van palette. <![CDATA[<b>A fuzzy methodology for local entrepreneurial culture evaluation: evidence from post-soviet Kyrgyzstan</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100009&lng=en&nrm=iso&tlng=en This paper assesses the local entrepreneurial culture based on the perceptions of local residents, by focusing on four distinct dimensions of the local entrepreneurial culture: 'diversity and change climate', 'business promotion climate', 'business discouragement climate', and 'focus on local'. A comprehensive survey was used to assess the local entrepreneurial culture in Bishkek, Kyrgyzstan. The items included in the survey were categorised as positive or negative statements that describe the respondent's county. This paper provides a framework that consists of a two-level model to construct a quantitative measure of local entrepreneurial culture. Essentially, a fuzzy artificial decision is based on data collected by conducting the survey with entrepreneurs and non-entrepreneurs. At the top level, a fuzzy multicriteria decision-making model was used to measure the local entrepreneurial culture. This model assesses the entrepreneurial culture in the community development practices of managers, contributes to future entrepreneurial research, identifies practices for entrepreneurial culture, and assesses the role of local cultural characteristics in entrepreneurship. This study includes a novel methodology, compared with those described in the literature, as it includes a conceptual model based on the perceptions of local residents. The results of this study showed that Bishkek's entrepreneurial culture is below the middle level.<hr/>'n Omvattende meningspeiling is gebruik die plaaslike entrepreneurskultuur in Bisjkek, Kirgisië te beoordeel. Dit word op grond van die persepsies van die plaaslike inwoners beoordeel deur vier dimensies van die plaaslike entrepreneurskultuur te ondersoek, naamlik diversiteit en veranderingsklimaat, besigheid-bevorderingsklimaat, besigheid-ontmoedigingsklimaat en die fokus op plaaslike belange. Die items in die meningspeiling is gekategoriseer as positiewe of negatiewe stellings wat die respondent se distrik beskryf. Hierdie artikel verskaf n raamwerk wat uit n tweevlakkige model bestaan en gebruik kan word as n kwantitatiewe maatstaf van plaaslike entrepreneurskultuur. n Wasige, kunsmatige besluit is gegrond op die meningspeiling terugvoer. Op die boonste van die twee vlakke is n wasige, multi kriteria besluitnemingsmodel gebruik om die plaaslike entrepreneurskapkultuur te meet. Die model assesseer die entrepreneurskultuur in die gemeenskapontwikkelingspraktyke van bestuurders, dit dra by tot toekomstige entrepreneurskapverwante navorsing en assesseer die rol van plaaslike kulturele eienskappe in entrepreneurskap. Hierdie studie sluit 'n nuwe metodologie in, teenoor dit wat in die literatuur beskryf is, omdat dit n konseptuele model gegrond op die plaaslike gemeenskap se persepsies insluit. Die resultate toon dat Bisjkek se entrepreneurskapkultuur ondergemiddeld is. <![CDATA[<b>An empirical study of the factors affecting the adoption of mobile enterprise applications</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100010&lng=en&nrm=iso&tlng=en Mobile enterprise application (MEA) technology has been identified as a technology that could help organisations to improve productivity, reduce cost, and gain and sustain competitive advantages through enterprise-wide technology implementations. Despite its many potential benefits, the adoption of MEA has not been as extensive globally as anticipated. Research results indicate that perceived technology usefulness, ease of use, perceived competitive pressure, industry trends, information technology (IT) infrastructure, organisational policies processes and systems, employee knowledge and readiness, and organisational resources are important factors that shape the adoption intent of organisations towards MEA technology. Implications for practice and research are also discussed.<hr/>Mobiele besigheidstoepassingstegnologie (MBTT) is geïdentifiseer as 'n tegnologie wat organisasies kan help om produktiwiteit te verbeter, koste te verminder, en mededingende voordele te verkry en te onderhou deur middel van omvattende implementering van die onderneming. Ten spyte van vele voordele, is die aanvaarding van MBTT nie so omvangryk wêreldwyd as wat verwag is nie. Navorsingsresultate dui daarop dat waargeneemde tegnologie bruikbaarheid, gemak van gebruik, waargeneemde mededingende druk, bedryfstendense, IT-infrastruktuur, organisatoriese beleidsprosesse en -stelsels, werknemerskennis en gereedheid, sowel as organisatoriese hulpbronne is belangrike faktore wat die aannemings-voorneme van organisasies vir MBTT vorm. Implikasies vir praktyk en navorsing word ook bespreek. <![CDATA[<b>The development of a healthcare innovation adoption readiness assessment tool (HIARAT)</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100011&lng=en&nrm=iso&tlng=en A disconnect exists between innovations and the adoption of such innovations, specifically within healthcare facilities. This disconnect results in various healthcare challenges - ones that could be addressed by successfully adopting and integrating an innovation into organisational processes - not being addressed. To address the challenge of innovation adoption within healthcare, it is proposed that a tool be developed to identify areas that should be addressed to improve the chances of the successful adoption and integration of innovations into existing systems in a public healthcare facility. By assessing a facility's readiness for innovation adoption, it is possible to identify the barriers to the successful adoption of innovations. Knowing what such challenges or barriers to innovation adoption are will allow role players to address these challenges or barriers. The purpose of this paper is to develop the healthcare innovation adoption readiness assessment tool (HIARAT), which measures the maturity of a healthcare facility's innovation adoption process. The HIARAT was validated through a face validation workshop, and through a case study at a South African public healthcare facility.<hr/>'n Ontkoppeling bestaan tussen innovasies en die aanneming van sulke innovasies, spesifiek binne gesondheidsorgfasiliteite. Hierdie ontkoppeling lei tot verskillende gesondheidsorguitdagings wat tans nie aangespreek word nie, maar wat aangespreek behoort te kan word deur die suksesvolle aanneming en integrasie van 'n innovasie in organisatoriese prosesse. Om die uitdaging van innovasie-aanneming binne gesondheidsorg aan te spreek, word voorgestel dat 'n instrument ontwikkel word om gebiede te identifiseer wat aangespreek moet word om die kanse van die suksesvolle aanneming en integrasie van innovasies in bestaande stelsels in 'n openbare gesondheidsorgfasiliteit te verbeter. Deur die beoordeling van 'n fasiliteit se gereedheid vir innovasie aanneming, is dit moontlik om die struikelblokke tot die suksesvolle aanneming van innovasies te identifiseer. Om te weet wat sulke uitdagings of hindernisse vir die aanneming van innovasies is, sal rolspelers in staat stel om hierdie uitdagings of hindernisse aan te spreek. Die doel van hierdie artikel is om die gesondheidsorg-innovasie-aannemingsgereedskap-assesserings-instrument (HIARAT) te ontwikkel, wat die volwassenheid van 'n gesondheidsorgfasiliteit se aannemingsproses meet. Die HIARAT is gevalideer deur middel van 'n gesigs-evaluasie werkswinkel, en deur middel van 'n gevallestudie by 'n Suid-Afrikaanse openbare gesondheidsorgfasiliteit. <![CDATA[<b>Simulation-aided value stream mapping for productivity progression in a steel shaft manufacturing environment</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100012&lng=en&nrm=iso&tlng=en Productivity improvement in the steel industry is pivotal to achieving competiveness that stimulate the economic growth of a country. In the past decade, the steel shaft manufacturing industry has experienced low productivity rates, making it difficult to compete at a global level. In light of this, the aim of this research study is to investigate the various process wastes and bottlenecks that limit the productivity progression of a steel shaft manufacturing environment, using integrated value stream mapping and system simulation methodologies. Data captured through the system observation of the shaft manufacturing process of a steel company was used to map and simulate the system. The results of the current state mapping of the steel shaft manufacturing environment revealed the various process wastes present in this system. The result of the simulation of the system revealed that the system bottlenecks were the saw master and milling stations. The strategic interventions in the saw master and milling stations improved these stations throughput from 959 to 1 218 (27%) and 624 to 1 003 (60.74%) components respectively. The work-in-progress components generated in the entire system after the strategic interventions reduced from 415 to 17.<hr/>Produksieverbetering in die staalindustrie is deurslaggewend om mededingendheid te behaal wat die ekonomie van 'n land stimuleer. In die afgelope dekade het die staal as vervaardigingindustrie lae produktiwiteit ervaar en dit maak dit moeilik om internasionaal mee te ding. Die doel van hierdie navorsing is om verskeie proses vermorsing en bottelnekke wat produksie beperk te ondersoek deur van geïntegreerde waardestroomkartering en stelsel simulasie metodologieë gebruik te maak. Data waargeneem in die as vervaardigingsproses van 'n staal maatskappy is gebruik om die stelsel te karteer en te simuleer. Die resultate van die huidige toestand kartering het verskeie proses vermorsings blootgestel. Die simulasie resultaat het getoon dat die proses-bottelnekke die meestersaag en die vreesmasjien stasie is. Strategiese ingrypings by die twee bottelnekke het die deurset onderskeidelik verhoog van 959 na 1218 (27%) en van 624 na 1003 (60.74%) komponente. Die werk-in-proses komponente in die algehele sisteem na die strategiese ingryping het verminder van 415 na 17. <![CDATA[<b>Analytic hierarchical method applied to brush cutter blade selection</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100013&lng=en&nrm=iso&tlng=en The objective of this work was to use the analytic hierarchic process (AHP) to select the best replacement brush cutter blades. The seven decision criteria of the AHP included three mechanical property criteria and four commercial data criteria. The mechanical property criteria were based on wear rate, impact toughness, and hardness, all of which were tested, while the four commercial data criteria were set on price, weight, packaging information, and product distribution, which were surveyed. Four replacement brush cutter steel blades of types 65C, 72C, 73C, and 81C were included. The best alternative was the 65C steel blade according to the AHP method.<hr/>Die doelwit van hierdie werk is om die analitiese hiërargieproses in te span om die beste plaasvervanger bossnyerlemme te kies. Die sewe besluitnemingskriteria van die analitiese hiërargieproses sluit drie meganiese eienskappe en vier kommersiële eienskappe in. Die meganiese eienskappe is gegrond op slytasietempo, impak taaiheid en hardheid (wat almal getoets is), terwyl die kommersiële kriteria gegrond is op prys, gewig, verpakkingsinligting sowel as produkverspreiding (wat almal ondersoek is). Vier plaasvervanger lemme (tipes 65C, 72C, 73C en 81C) is by die ondersoek ingesluit. Die beste alternatief was 'n 65C staal lem. <![CDATA[<b>Cost and productivity analysis of the manufacturing industry using TDABC & MOST</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100014&lng=en&nrm=iso&tlng=en Costing is important for manufacturing industries. Large methods of costing have evolved over time. Recently, the time-driven activity-based costing (TDABC) system has gained importance and application. This article describes the procedure that allows companies to implement TDABC using the Maynard operation sequence technique (MOST) for improving productivity and profitability. Two parameters are required for TDABC: (1) the unit cost of supplying capacity, and (2) the time required to perform a transaction or an activity. MOST is employed to estimate the time required for each activity. Based on this, time equations are formulated and the practical capacity of activities is determined. The procedure is explained with the help of a case study from a manufacturing industry. The results of the case study are discussed from the perspective of the overall company and also at the product level. This approach provides the capacity analysis and the cost analysis together with its hierarchical decomposition. This paper also discusses the different information obtained from TDABC, and its usefulness for managers and decision-makers.<hr/>Kosteberaming is belangrik vir die vervaardigingindustrie. Verskeie kosteberamingmetodes is met die verloop van tyd ontwikkel. Tydgedrewe aktiwiteitsgebaseerde kosteberaming (TDABC) het onlangs aan die lig gekom en word in hierdie artikel bespreek, spesifiek met die klem op die prosedure om TDABC te implementeer deur middel van die Maynard operasie sekwensiële tegniek (MOST) om sodoende produktiwiteit en winsgewendheid te verbeter. Twee parameters word vir TDABC benodig, naamlik (1) die eenheidskoste van voorsieningskapasiteit en (2) die tyd benodig om 'n transaksie of aktiwiteit te verrig. MOST word ingespan om die tyd vir elke aktiwiteit te skat. Op grond hiervan word tydvergelykings opgestel en die praktiese kapasiteit van aktiwiteite bepaal. Die prosedure word toegelig met die hulp van 'n gevallestudie vanuit die vervaardigingindustrie. Die gevallestudie resultate is bespreek vanuit die algehele maatskappy se perspektief asook op produkvlak. Hierdie benadering verskaf die kapasiteit en die koste analise saam met die hiërargiese samestelling. Die artikel bespreek ook die informasie wat vanuit die TDABC verkry word en die nut daarvan vir bestuurders en besluitnemers. <![CDATA[<b>A lexicographical method for a production planning problem in an engineering industry: a case study</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100015&lng=en&nrm=iso&tlng=en This paper deals mainly with the existing practices of production planning in a single-piece flow-based cellular manufacturing process making auto-electrical parts. Based on historical data from a case study industry, we identified multiple significant and relevant production planning objectives. This paper discusses a lexicographical method to solve the multi-objective programming model for workforce distribution to optimise production planning. This approach offers an opportunity to develop a better understanding of workforce distribution and the importance of the multiproduction channel, with insights into further production planning.<hr/>Hierdie artikel handel oor die bestaande praktyke van produksie-beplanning in 'n enkelstuk vloeigebasseerde sellulêre vervaardigingsproses wat outo-eletriese onderdele vervaardig. Gegrond op historiese data van 'n gevallestudie is verskeie noemenswaardige en relevante produksiebeplanningsmikpunte identifiseer. Die artikel ondersoek 'n leksikografiese metode om die multi-doelstelling programmeringsmodel vir werksmag-verdeling vir optimale produksiebeplanning op te los. Die benadering bied 'n geleentheid om 'n beter verstaan van werksmag-verdeling te ontwikkel asook die belangrikheid van die multi-produksie kanaal. Dit bied verdere insigte tot produksiebeplanning. <![CDATA[<b>A framework for lean readiness evaluation using a hierarchical fuzzy system</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100016&lng=en&nrm=iso&tlng=en Lean manufacturing is becoming the frontrunner in solving manufacturing-related problems. To sustain the lean journey, assessing lean readiness is the appropriate way to implement it in any industry. In this research, lean readiness is evaluated in a case study industry using a framework model. It consists of two dimensions: the critical success factors, and the barriers. Using force field analysis, the conflicting nature of these dimensions was portrayed. With the help of fuzzy logic, a hierarchical fuzzy system was developed to evaluate lean readiness. The result of this method opens up a new direction for managers to identify lean readiness.<hr/>Lenige vervaardiging is die voorloper om vervaardiging verwante uitdagings aan te spreek. Dit is egter belangrik vir volhoubaarheid om die gereedheid om van lenige vervaardiging gebruik te maak, te bepaal. Lenige gereedheid word deur middel van 'n gevallestudie beoordeel met die gebruik van 'n raamwerk model. Dit bestaan uit twee dimensies, naamlik die kritiese suksesfaktore en die hindernisse. Die teenstrydige aard van hierdie twee faktore is uitgebeeld deur kragveldanalise. Met die hulp van die wasigheidsleer is 'n wasige hiërargiese stelsel ontwikkel om lenige gereedheid te evalueer. Die resultaat van hierdie metode skep n nuwe metode vir bestuurders om lenige gereedheid te identifiseer. <![CDATA[<b>Improving the response time for the corrective maintenance of rail infrastructure: a case study of the Western Cape Passenger Rail Network</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100017&lng=en&nrm=iso&tlng=en Response time for repairing rail infrastructure failures remains a challenge in the South African rail industry. The 'mean time to return' metric consists of mean time to respond and mean time to repair. This article investigates the mean time to respond for signalling infrastructure at the Passenger Rail Agency of South Africa (PRASA) in the Western Cape, and introduces a strategy to reduce downtime. The results show that the time of occurrence, the location, and the nature of incidents, as well as the location of maintenance personnel, influence the time to respond. A model is developed to assist with improved decision-making.<hr/>Reageertyd vir die herstel van onvoorsiene falings bly 'n realiteit in die Suid-Afrikaanse spoorwegindustrie. Die 'gemiddelde tyd tot terugkeer' meting bestaan uit die gemiddelde tyd om te reageer en die gemiddelde tyd om te herstel. Hierdie artikel ondersoek die gemiddelde tyd om te reageer vir sinjaalinfrastruktuur by die Passasierspooragentskap van Suid-Afrika (PRASA) in die Wes-Kaap, en stel 'n reaksiestrategie voor om staantyd te verminder. Die resultate toon dat die tyd van voorkoms, die ligging en die aard van voorvalle, asook die ligging van instandhoudingspersoneel, die tyd om te reageer beïnvloed. 'n Model is ontwikkel om te help met verbeterde besluitneming. <![CDATA[<b>Classification and prediction of wafer probe yield in DRAM manufacturing using Mahalanobis-Taguchi system and neural network</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100018&lng=en&nrm=iso&tlng=en Wafer yield is a key indicator to pursuing excellence in semiconductor manufacturing. With the increased wafer size, the enhanced complexity and precision of wafer fabrication is possible. Using monitoring to improve the process by predicting the yield has become an important quality issue. Most research uses the number of wafer defects, the area of the wafer, and fixed statistical distribution to predict the yield. Such methods fail to establish a high yield model due to the random and system-wide distribution of wafer defects. This study proposes the Mahalanobis-Taguchi system (MTS) to determine the key variables from the wafer acceptance test (WAT), and establish a classification model of yield grade. The general regression neural network (GRNN) was used to build a predicted model of the wafer probe yield from selected common variables. A real case from a Taiwan manufacturer of dynamic random-access memory (DRAM) is used as an example. It can get the 82 key and significant sequence variables of the WAT, with classification precision of over 90/ and the R² of the GRNN prediction model at 0.73. Through demonstration, the result can effectively increase the yield and reduce the quality cost in DRAM manufacturing.<hr/>Flinteropbrengs is 'n sleutel indikator vir halfgeleiervervaardiging. Die toename in flintergrootte maak dit moontlik om die kompleksiteit en presisie van flintervervaardiging te verbeter. Wanneer monitering gebruik word om die opbrengsskatting te verbeter word dit 'n gehalte kwessie. Die meeste navorsing gebruik die aantal defekte, die flinteroppervlakte, en vasgestelde statistiese verdelings om die opbrengs te skat. Sulke metodes faal egter om 'n hoë-opbrengs model te bewerkstellig as gevolg van die lukrake en stelselwye verspreiding van defekte. Hierdie studie gebruik die Mahalanobis-Taguchi stelsel om die sleutel veranderlikes van die flinter aanvaardingstoets te bepaal en skep dan n klassifikasie model van die opbrengsgehalte. n Veralgemeende regressie neurale netwerk is gebruik om 'n skatting van die opbrengs te maak van gekose gemeenskaplike veranderlikes. 'n Gevallestudie van 'n Taiwannese vervaardiger van dinamies ewetoeganklike geheue word as voorbeeld gebruik. Die benadering kan twee-en-tagtig van die sleutel en noemenswaardige veranderlikes van die aanvaringstoets identifiseer met n klassifikasiepresisie van meer as negentig persent. Die R²-koëffisiënt van die neurale netwerk is 0.73. Die resultaat kan die opbrengs verhoog en die gehaltekoste van dinamies ewetoeganklike geheue vervaardiging verminder. <![CDATA[<b>Effect of scope readiness on capital projects in mining: a Namibian case study</b>]]> http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2224-78902019000100019&lng=en&nrm=iso&tlng=en Although project scope definition is regarded as a key element in successful project management, research on the subject is sparse. This paper investigates the relationship between project scope readiness and project performance in the Namibian mining industry. A survey was done on ten projects from seven Namibian mining companies, using the project definition readiness index (PDRI) tool as a scope definition indicator, while cost and schedule performance were used as performance indicators. Support was found for the proposition that readiness of project scope definition improves schedule performance, but the relationship between the PDRI score and cost performance was less conclusive.<hr/>Alhoewel die bestek-beskrywing van 'n projek algemeen beskou word as 'n sleutelelement in die suksesvolle bestuur van 'n projek, is baie min navorsing hieroor gedoen. Hierdie artikel ondersoek die verwantskap tussen die gereedheid van bestek-beskrywings en die sukses van projekte in die Namibiese mynbou-industrie. 'n Opname is gedoen op tien projekte in sewe Namibiese mynbou maatskappye. Die Projek Definisie Gereedheid Indeks (PDRI) instrument is gebruik as aanwyser van die gereedheid van die bestekdefinisie, terwyl kosteprestasie en skedule-prestasie as aanduiding van projeksukses gebruik is. Ondersteuning is gevind vir die stelling dat die gereedheid van 'n projek se bestekomskrywing skedule-prestasie bevorder, maar die verwantskap tussen PDRI telling en kosteprestasie was minder oortuigend.