Faculty of Engineering and Built Environment
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Item An evaluation of the applicability of the extended situational leadership model to lower level management in the South African construction industry(University of the Witwatersrand, 1990-08-10) Cocotos, GeorgeThe vast majority of theories and models that have been developed around the concept of leadership have been conceptualized, and tested in the USA and other countries outside South Africa as discussed in the literature survey, Chapter 2 of this dissertation). Furthermore, the models developed have largely been theoretical models aimed to help leaders only to identify the most appropriate leadership style to use. None have however attempted to develop a model that leaders can use to implement the most appropriate leadership style once it has been chosen. Consequently, A D Jaff, using the most integrated and recently developed Situational Leadership Theory and Mode 1 of Hersey and Blanchard as a data base, developed the first leadership implementation model - The Extended Situational Leadership Model. Since AD Jaff's implementation model is a combination of various other leadership mode ls and theories, in order to fully understand the development of the Extended SL Model, all the relevant models are researched in this dissertation (see Chapter 2). This dissertation attempts to test the applicability of the Extended SL Model in a practical construction environment in South Africa. It further attempts to make adaptations to the model where relevant, after testing its performance value through the administration of 3 questionnaires to a sample of potential/practising black leaders (on-site construction managers). (This lS surveyed in Chapters 3 to 6 of this dissertation). The objective of this dissertation is therefore to attempt to test, and where necessary, to adapt AD Jaff's Extended SL Model so that : 1) this theoretical model may be implemented practically in a South African construction working environment (i.e. to prove that the mode 1 does work in practice) ( see Chapter 4). and to test whether 2) the adapted mode 1 is applicable for the training of future black Low-Level leaders in the South African construction environment. The adapted form of the model will, I believe, prove to be a useful tool for the training of black leaders within the South African construction organisations, where the volatile industry and changing economic and political environment of South Africa with ensure the emergence of black South African Low Level leaders in the construction industry in the near future.Item Just-in-time development model for a sub-level caving underground mine in Zimbabwe.(The Southern African Institute of Mining and Metallurgy., 2003-04) Musingwini, C.; Minnitt, R.C.A.; Phuti, D.; Makwara, F.Traditionally, mineral reserves management at most underground mines in Zimbabwe focus on maintaining large mineral reserves so that the time between development and production is as long as possible. Historical data at Shabanie mine, a Zimbabwean sub-level caving underground mining operation, confirms this practice. However, the high cost of underground development means that the luxury of large buffer mineral reserves cannot be justified. Furthermore significant increases in the costs of production, exacerbated by the current unfavourable economic climate, make the wisdom of extending development workings well ahead of use questionable. Poor ground conditions at Shabanie mine, mean that some development ends have to be re-mined two or three times due to partial or complete closure between the time they are mined and the time they are utilized. In order to reduce the inordinately high support costs associated with closure of development ends a new 'Just-in-time' (JIT) approach that provides development ends as and when they are needed, has been adopted. Accordingly a model to determine an appropriate 'just-in-time' rate of development has been created. The JIT development model indicated that the mine could reduce development rates from 330 m/month in 2001, to 160 m/month in 2002 and achieve savings of about 50% on annual support costs, but still assure customers of a long-term product supply. The mine accepted the model in November 2001 and began implementing it in 2002. Results of the implementation will be reviewed in 2003.Item First cycle experience of a business process re-engineering programme at Shabanie Mine.(The Southern African Institute of Mining and Metallurgy., 2005-04) Musingwini, C.; Muzoriwa, C.; Phuti, D.; Mbirikira, D.In the past ten to fifteen years, many organizations have applied business process re-engineering (BPR) to significantly improve their business competitiveness or stave off closures. The mining industry in Southern Africa is no exception and documented examples can be drawn from South Africa. Although the concept is superficially simple, its application has been marked by a high failure rate of about 70 per cent because it has been generally misunderstood. Shabanie mine, a chrysotile asbestos fibre producer in Zimbabwe took cognisance of this fact by cautiously embarking on a modular BPR programme in October of 2002. A year was used as a complete cycle or module for re-evaluation of the programme. Shabanie mine adopted BPR as part of management efforts to remain competitive amid serious threats to operational viability. These threats included hyper-inflation driven rising production costs, a declining world asbestos market and a possibility that Russia could take over the shrinking world asbestos market by dumping low-priced asbestos fibre. The only competitive advantage that the mine had was the high quality of its long-fibre chrysotile asbestos. The major BPR thrust was therefore to redesign processes for improved productivity and ultimately achieve a lower cost per ton of final asbestos fibre product. In addition, corporate culture change and cost-saving were also factored into the programme. This paper discusses the implementation experience of the BPR programme at the mine. The main BPR beneficial highlights are improved productivity, sizeable cost-savings, positive corporate culture change and identification of secondary projects. One of the lessons learnt from this programme is that mining companies will have to deal with the HIV/AIDS pandemic if they are to sustain high levels of productivity into the future.Item Technical operating flexibility in the analysis of mine layouts and schedules.(The Southern African Institute of Mining and Metallurgy., 2007-02) Musingwini, C.; Minnitt, R.C.A.; Woodhall, M.Often overlooked factor in the analysis of mine layouts and schedules is technical operating flexibility (or tactical flexibility), mainly due to its nebulous nature. By glossing over technical operating flexibility the resultant mine layouts and schedules may be suboptimal. The need to incorporate technical operating flexibility into the analysis and comparison of mine layouts and schedules is increasing in importance. The nature of technical operating flexibility is illustrated, previous work on valuing of operating flexibility reviewed, and a proposal made on how technical operating flexibility can be quantified for tabular reef mines by using a platinum reef deposit as a case study. Once technical operating flexibility has been quantified it becomes possible to explore its incorporation into the analysis of mine layouts and schedules and subsequent optimization processes. This paper is a revised version of a paper presented in the Proceedings of the Second International Platinum Conference, 'Platinum Surges Ahead' in 2006. The work described in this paper is part of a current PhD study at the University of the Witwatersrand.Item Modelling open pit shovel-truck systems using the Machine Repair Model.(The Southern African Institute of Mining and Metallurgy., 2007-08) Krause, A.; Musingwini, C.Shovel-truck systems for loading and hauling material in open pit mines are now routinely analysed using simulation models or off-the-shelf simulation software packages, which can be very expensive for once-off or occasional use. The simulation models invariably produce different estimations of fleet sizes due to their differing estimations of cycle time. No single model or package can accurately estimate the required fleet size because the fleet operating parameters are characteristically random and dynamic. In order to improve confidence in sizing the fleet for a mining project, at least two estimation models should be used. This paper demonstrates that the Machine Repair Model can be modified and used as a model for estimating truck fleet size in an open pit shovel-truck system. The modified Machine Repair Model is first applied to a virtual open pit mine case study. The results compare favourably to output from other estimation models using the same input parameters for the virtual mine. The modified Machine Repair Model is further applied to an existing open pit coal operation, the Kwagga Section of Optimum Colliery as a case study. Again the results confirm those obtained from the virtual mine case study. It is concluded that the Machine Repair Model can be an affordable model compared to off-the-shelf generic software because it is easily modelled in Microsoft Excel, a software platform that most mines already use. This paper reports part of the work of a MSc research study submitted to the University of Witwatersrand, Johannesburg, South Africa.Item Clinic Building(Self published, 1980-01) Nimpuno, KrisnoThe objective of constructing low cost health buildings is not simply to build cheaply, but rather to construct fully adequate facilities for the lowest possible cost; or, in other words, to achieve a maximum health care capacity from each invested dollar. This may seem to be a very superficial remark, but there are in reality staggering differences in costs between hospitals of equal capacity within almost each of the LDCs, which give us ample reason for questioning the present practice. Does anyone really, helieve that ,medical €are .is ten times more effective in a ten times costlier hospital bed? Does anybody believe that a reasonable hospital bed/population ratio can be achieved with high rise, air conditioned hospitals in countries with a GNP/Capital of less than $500:- per annum? The answer is naturally no. Nobody believes that. But why do governments and technical assistance agencies build such costly facilities? The answer is that the elites taking those decisions are not sincere in their proclaimed efforts to provide equal care for the whole nation.Item Metropolis; architectural students congress(Architectural Students Congress Committee, 1986-04) Elk, Clifford (ed) et alWe are of Africa, and have been misguided and mislead into thinking that our cultural and architectural aspirations should coincide with other Western Nations of the world, best demonstrated by not only the content of our education but also by the state of the architectural profession. This is precisely the stand that the congress took, being highly critical of the imagery and ideas imported per se, while attempting to redress the question of relevancy, symbolism and meaning of architecture in South Africa today, the role that the architect plays and how our education currently fashions our perception.Item A novel method to measure residual stresses in unidirectional GFRP.(Elsevier, 2009-05) Reid, R.G.; Paskaramoorthy, R.A few methods are available for measuring the residual stresses that occur in the simplest of all possible composites structures - the unconstrained unidirectional laminate. None of them, however, are suitable for use on GFRP. A new method is presented whereby the stresses in a unidirectional GFRP laminate can be determined. The method relies on releasing the constraints between fibre and resin through an annealing process. The strain in the glass fibres is thus obtained, which allows the elastic stresses within the fibres and the resin to be determined. In this way, it is not necessary to take account of plasticity and viscous effects in the polymer in order to determine the stresses within the laminate. Results for unidirectional laminates initially manufactured to contain differing residual stresses are presented and discussed.Item Undergraduate engineering training through institutional collaboration in the Southern African region.(Higher Education South Africa (HESA)., 2005) Ilemobade, A.A.; Ballim, Y.The University of the Witwatersrand (Wits) and The University of Namibia (UNAM) signed an Agreement of Co-operation (AOC) in 2000. This agreement, which formalised an existing informal collaboration, was primarily targeted at facilitating the transfer of potential Unam undergraduate engineering students to pursue engineering studies at the WITS Faculty of Engineering as well as improving staff collaboration in research and teaching. Students from UNAM's pre-engineering programme and science departments have been beneficiaries of this agreement. Four years later, an evaluation of the collaboration reveals critical issues vis-à-vis decreasing student enrolments, unimpressive student graduation rates, and financial and operational complexities affecting student mobility - all of which have institutional as well as regional implications. This paper presents highlights and pertinent lessons of the collaboration, and recommendations for similar collaboration in the Southern African region both at an institutional and regional level. As a whole, the paper uses the Wits experience to extrapolate principles and strategic issues facing institutions involved in academic collaboration and cross-border movement of students within the Southern Africa region.Item Waste to wealth: A case study of the ondo state integrated wastes recycling and treatment project, Nigeria.(EuroJournals, Inc., 2009) Olanrewaju, O.O.; Ilemobade, A.A.The Ondo State Integrated Waste Recycling and Treatment Project, came into existence in June 2006 with the commissioning of the project office complex along Igbatoro Road, Akure by the Nigeria President, Chief Olusegun Obasanjo. The Project started operation in December 2006 with the aim of minimising solid waste in Akure and its environs. Since its inception, OSIWRTP has recorded huge successes in transforming the waste generated in Ondo State to wealth by the development of various valuable products using the basic concepts of sustainability: social progression, technical and technological improvements, environmental protection and economic development. Such waste is been generated from agricultural waste, nylon and plastic waste and foundry (metal) waste. Several techniques have been used to transform the waste into profitable products e.g. using anaerobic digestion (biogas) to produce energy and fertilizer; composting for soil conditioner; scrap iron for foundry products and other recycling techniques for solid wastes. The main output of OSIWRTP as at today are fertiliser, foundry materials and other recycled materials depending on the availability of wastes, and according to demands and need.