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A systems dynamic approach to channel management

- Dirker, H.G., Pretorius, L., Pretorius, J.H.C.

  • Authors: Dirker, H.G. , Pretorius, L. , Pretorius, J.H.C.
  • Date: 2009
  • Subjects: Distribution channels management , Control and instrumentation products , Systems dynamic modelling , Channel management
  • Type: Article
  • Identifier: uj:6206 , ISSN 0-9815817-2-2 , http://hdl.handle.net/10210/5290
  • Description: The purpose of this paper is to explore from a systems dynamic modelling approach ways in which to manage distribution channels in the control and instrumentation product market. In this market multi-faceted product lines, technological knowledge and the position of the product in its life cycle play important roles in the manner in which these products are diffused into the market. Due to the fast pace of emerging technologies, it is becoming increasingly difficult for manufacturers to keep their routes to the markets aligned to ensure profitability and customer satisfaction. Aims of the paper include the following: to asses whether driving factors identified by way of preliminary research case studies, qualitative methods and inductive reasoning are realistic and how the identified factors could be used within a systems dynamic modelling approach to understand the value additions derived from a distribution channel for the various types of product lines. In conducting the research, unlike many studies using qualitative methods, this paper additionally employs system dynamics simulation to develop an analysis of different scenarios that can be used by manufacturers in their channel management approach. This paper contributes to the field of technology business strategies and planning by introducing a systems dynamic model that can be of assistance to technology manufacturers to ascertain the appropriate route to market for their various product lines.
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An approach to innovation in risk systems

- Barkhuizen, W.F., Pretorius, J.H.C., Pretorius, L.

  • Authors: Barkhuizen, W.F. , Pretorius, J.H.C. , Pretorius, L.
  • Date: 2011
  • Subjects: Risk interactions , Fuzzy logic thinking
  • Type: Article
  • Identifier: uj:6043 , http://hdl.handle.net/10210/10449
  • Description: Risk interactions exist between functional and physical elements within a system and its sub-systems in various ”dimensions” such as spatial interaction, information exchange, material transfer, energy exchange etc. The interactions are of a multi-dimensional complexity that cannot be sufficiently interpreted using conventional management tools (PERT, Gantt and CPM methods). Alternative system representation and analysis techniques are proposed, in particular the design structure matrix (DSM), and fuzzy logic thinking to quantify the risk management effort necessary to deal with uncertain and imprecise interactions. A Cement Grinding Plant case study is utilized to elaborate on the risk management methodology.
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An integrated systems approach to risk management within a technology-driven industry, using the design structure matrix and fuzzy logic

- Barkhuizen, W.F., Pretorius, J.H.C., Pretorius, L.

  • Authors: Barkhuizen, W.F. , Pretorius, J.H.C. , Pretorius, L.
  • Date: 2012
  • Subjects: Fuzzy logic thinking , Risk management
  • Type: Article
  • Identifier: uj:4661 , ISSN 2224-7890 , http://hdl.handle.net/10210/10034
  • Description: Risk interactions exist within a system and its sub-systems, between functional and physical elements in various dimensions such as spatial interaction, information exchange, material transfer, and energy exchange. These interactions are of a multi-dimensional complexity, and thus are not sufficiently interpreted using conventional management tools. Alternative system representation and analysis techniques are proposed – in particular the design structure matrix (DSM) and fuzzy logic thinking – to quantify the risk management effort necessary to deal with uncertain and imprecise interactions. A cement grinding plant case study is used to elaborate on the risk management methodology
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The impact of the converter modes on the distribution of active harmonic powers

- Bokoro, N.P., Pretorius, J.H.C.

Energy savings reporting and uncertainty in measurement & verification

- Akinsooto, O., Pretorius, J.H.C., De Canha, D.

  • Authors: Akinsooto, O. , Pretorius, J.H.C. , De Canha, D.
  • Date: 2014
  • Subjects: Energy savings , International Performance Measurement and Verification Protocol
  • Type: Article
  • Identifier: uj:4990 , http://hdl.handle.net/10210/13125
  • Description: This paper provides more detailed information on the application of the International Performance Measurement and Verification Protocol (IPMVP) guideline in the determination and reporting of energy savings. It stresses the need, the importance and an approach that can be used to report energy savings accurately in Measurement and Verification (M&V). The paper focusses on the fundamentals and the applications of the IPMVP in the determination and reporting of energy savings that result from energy efficiency intervention. The methodology applied here can be used to ensure complete compliance with the IPMVP guideline.
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Measurement & verification of a utility sponsored residential demand side management programme involving multiple technologies

- De Canha, D., Pretorius, J.H.C.

  • Authors: De Canha, D. , Pretorius, J.H.C.
  • Date: 2014
  • Subjects: Energy efficiency - South Africa , Load shifting
  • Type: Article
  • Identifier: uj:5008 , http://hdl.handle.net/10210/13148
  • Description: Due to the low reserve margin on the electrical grid in South Africa many energy initiatives were introduced by the utility over the last decade. One such initiative was to roll out identified energy efficiency technologies at residential homes. The utility aimed to achieve a 90MW evening peak (18h00 to 20h00) demand reduction by distributing free CFLs, LEDs, geyser timers, pool timers and low flow shower roses to residential electricity customers throughout the country. This paper presents an overview of the process and methodology used to measure and verify (M&V) the energy and demand impact of the programme. The verified saving achieved was 87.2MW. This includes both an energy efficiency and a load shifting component. The project was M&V’d using the International Performance Measurement & Verification Protocol (IPMVP) and SANS 50010 standard for determining energy savings.
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Prototyping during the requirements elicitation process in the development of an underground unmanned aerial system

- Green, Jeremy, Marnewick, A., Pretorius, J.H.C.

  • Authors: Green, Jeremy , Marnewick, A. , Pretorius, J.H.C.
  • Date: 2015
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/87796 , uj:19624 , Citation: Green, J., Marnewick, A. & Pretorius, J.H.C. 2015. Prototyping during the requirements elicitation process in the development of an underground unmanned aerial system.
  • Description: Abstract: Prototyping of subsystem and system components is most often thought of as a development task. This paper shows the usefulness of prototyping as an activity in the requirements elicitation process, prior to any developement activities. It is approached from the field of engineering and technology management. It uses the Requirements Engineering approach to identify tools and methods for the development of the requirements for an underground unmanned aerial system for use in South Africa’s’ gold mines to inspect box-holes and ore-passes. Box-holes and ore-passes are vertical tunnels through which the ore must pass in moving from the stope, where it is mined, to the shaft, where it is hauled to the surface for processing. The more familiar new product development framework is compared to the requirement engineering process. The prototypes of a number of subsystems are presented, namely, a quadrotor platform, a platform preservation sensor array, an optical flow sensor for position holding, a vision sensor for operator visualization, and an operator interface. The perceived significant technological challenges are discussed as motivation in the choice of these subsystem prototypes that will be used in the interviews that are to form the basis of the requirements elicitation activity.
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Utilising high and premium efficiency three phase motors with VFDs in a public water supply system

- Van Rhyn, P., Pretorius, J.H.C.

  • Authors: Van Rhyn, P. , Pretorius, J.H.C.
  • Date: 2015-05-13
  • Subjects: Centrifugal pump systems , Energy efficiency , Variable frequency drives
  • Type: Article
  • Identifier: uj:5107 , ISBN 978-1-4799-9978-1 , http://hdl.handle.net/10210/13929
  • Description: The increased reliability and ultimately reduced life cycle cost of high and premium efficiency three phase motors in a process control application is discussed. The reduced energy consumption of these motors is evaluated in a public water system case study under variable frequency conditions. The importance of the consideration of a combined system, which includes variable speed control, motor and load - as opposed to only replacing with high efficiency motors for energy saving purposes - is practically observed and reported on. The paper reports on the marginal improvement in energy consumption at reduced supply frequency for motor replacement only (not surprising) but a very impressive 46% saving in energy consumption by controlling pumped water at a reduced but constant delivery rate.
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Effectiveness of economic incentives on clients’ participation in health and safety programmes

- Musonda, I., Pretorius, J.H.C.

  • Authors: Musonda, I. , Pretorius, J.H.C.
  • Date: 2015-06
  • Subjects: Economic incentives , Health and safety programmes , Construction industry - Safety measures , Occupational health and safety
  • Type: Article
  • Identifier: uj:5138 , ISSN 1021-2019 , http://hdl.handle.net/10210/14105
  • Description: The use of economic incentives to improve health and safety (H&S) performance in the construction industry in general has been investigated by various scholars. However, few studies have looked at the impact of economic incentives on construction clients, especially in the developing world. This paper reports findings on the feasibility of incentives to influence construction clients to perform on H&S. The investigation was conducted using a Delphi technique to determine the impact significance of economic incentives or disincentives on construction clients’ H&S performance. A panel of experts in construction H&S was assembled from most regions of the world. A three- round iterative Delphi study aimed at establishing consensus from the expert panel was then conducted. The study found that economic factors have critical impact significance on clients’ H&S performance, and that clients were ‘very likely’ to implement various H&S elements as a result of the economic incentives and or disincentives. There is little research on the use of incentives to influence construction clients’ H&S performance and the effectiveness of such incentives. This gap in literature, and the need for improvement in construction H&S performance, motivated the current study. Therefore it was necessary to investigate specifically the extent to which economic incentives could be used to influence construction clients to become involved in H&S programmes. Economic incentives are considered to be a proactive way of improving H&S performance among other key parties, such as employees in the construction industry. The paper reports on the findings from an analysis of the impact significance of economic incentives on clients. It underscores the point that economic incentives or disincentives for construction clients are necessary to encourage them to actively participate in H&S programmes, hence resulting in performance improvement.
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Total quality management adoption by process engineering design firms in South Africa

- Njenge, L., Vermeulen, Andre, Pretorius, J.H.C.

  • Authors: Njenge, L. , Vermeulen, Andre , Pretorius, J.H.C.
  • Date: 2015-06-08
  • Subjects: Product quality , Total quality management , Process engineering - South Africa
  • Type: Article
  • Identifier: uj:5133 , ISBN 9781775921110 , http://hdl.handle.net/10210/14099
  • Description: The study investigates the effects of Total Quality Management (TQM) implementation on process engineering design firms. Secondly, the study investigates the extent of TQM adoption by South African process engineering design firms. Lastly, the study investigates the perceived importance of TQM principles. The study reveals that 70% of the firms which participated in the survey have formally adopted TQM while 30% have not. Although the firms which have not formally adopted TQM are implementing TQM principles, they have not been able to implement the principles as well as the firms which have formally adopted TQM. It also reveals that TQM implementation improves employee satisfaction, customer satisfaction, and financial performance while providing a vision that channels the entire organisation towards improvements in product quality and customer†related performances
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A refined baseline methodology for large scale lighting retrofit projects

- Mvudi, Y., Chan Wing, S.N., Pretorius, J.H.C., Beya, M.M., Ndlovu, S.M.

  • Authors: Mvudi, Y. , Chan Wing, S.N. , Pretorius, J.H.C. , Beya, M.M. , Ndlovu, S.M.
  • Date: 2016
  • Language: English
  • Type: Conference proceeding
  • Identifier: http://hdl.handle.net/10210/92067 , uj:20181 , Citation: Mvudi, Y. et al. 2016. A refined baseline methodology for large scale lighting retrofit projects.
  • Description: Abstract: The residential sector is one of the major consumers of energy produced in the world. According to International Energy Balances (IEA, 2013), the residential sector demand represents about a quarter of the primary energy used in the world. Therefore, most energy efficiency programmes targeting large savings on a national or regional level pay particular attention to the opportunities in the residential sector. Lighting retrofitting on a large number of sites constitutes one of the most used strategies of energy conservation in the residential sector. However, given the large number of sites involved in this type of project, conventional measurement and verification (M&V) techniques based on the audit of each site, are not cost effective. Often, a statistical assessment approach based on the audit of a limited number of sites is the methodology used to mitigate the cost and the logistical challenges associated with the project. The major challenge in projects of this nature is to accurately estimate the energy consumption of a large number of sites using the measurement performed on a sample of sites selected from the overall population. In this research, baseline methodologies used in a selected number of light retrofitting projects have been analysed and, based on the observations made during this analysis, some improvements are suggested. The proposed methodology has been tested on a number of residences located on the premises of the University of Johannesburg. This paper describes the existing baseline methodologies and presents the improvements suggested to enhance the credibility of M&V results. The key results of the experimental phase of this project are also presented in this paper.
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A systematic approach for the implementation of an effective management model for gland service

- Robinson, G.S., Pretorius, J.H.C., Pretorius, L.

  • Authors: Robinson, G.S. , Pretorius, J.H.C. , Pretorius, L.
  • Date: 2016
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93285 , uj:20327 , Citation: Robinson,G.S., Pretorius, J.H.C. & Pretorius, L. 2016. A systematic approach for the implementation of an effective management model for gland service.
  • Description: Abstract:The aim of the research was to develop an Effective Management Model (EMM) for a Gland Service System (GSS). The Systematic Approach to Engineering Design focuses on the optimisation of the GSS which is a fundamental pillar for the functionality of the slurry pumps in a tailings plant. The EMM was considered for a wide variety of mining applications to innovatively create a method for the correct design, implementation, control and maintenance of a Gland Service System. A Production Performance Model (PPM) was created utilising the Overall Equipment Effectiveness (OEE) Theory to provide an indication of the production capacity of a tailings plant. The subsystem of the PPM was the EMM, its core focus was on the optimisation of the Gland Service System, which in turn directly relates the improved performance of the tailings plant which ultimately results in the improved capability of the mines production process. Simulink was used to incorporate the optimisation inputs of the GSS, thus forming a model from Qualitative and Quantitative feedback as well as the Experimentation with regard to water quality and its effect on the GSS. By using these data sets, triangulation of the data sampling systems was used. The combination of non-probability sampling, and purpose sampling systems formed the basis of the triangulation system.
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Applying preventive and predictive best practice on plant maintenance

- Tshabuse, F., Pretorius, J.H.C.

  • Authors: Tshabuse, F. , Pretorius, J.H.C.
  • Date: 2016
  • Subjects: Predictive , Preventive , Maintenance
  • Language: English
  • Type: Article
  • Identifier: http://ujcontent.uj.ac.za8080/10210/363275 , http://hdl.handle.net/10210/214779 , uj:21323 , Citation: Tshabuse, F. & Pretorius, J.H.C. 2016. Applying preventive and predictive best practice on plant maintenance.
  • Description: Abstract: Quite often in the industrial environment engineers are required to justify the addition or change of equipment when companies venture into investing in capital to increase production capacity or improve efficiency. Aged and outdated machinery and equipment are at times not economical to re-fabricate due to the improvement in manufacturing methods and obsolescence of old technology. Maintenance of machinery is often not done as it should be to achieve optimum availability where policies don’t exist. Technological improvement has resulted in less robust, advanced and often more complex designs where modern technology replaces older designs making the old designs more expensive to produce in some cases. As a consequence the re-fabrication of old equipment becomes difficult to justify with the high cost. The maintenance cost of previous equipment also does not compare to modern equipment and negatively affects the competitiveness of organisations against their peers that utilize modern methods. The solution to staying competitive is to re-design, upgrade equipment, change maintenance policy or introduce technology. This research will highlight methods that can be utilized to ensure that the reliability of equipment remains at an acceptable level and also show evidence of improvement in reliability of equipment due to re-design and through continuous improvement initiatives. A case study for design and continuous improvement efforts with primary and secondary data sourced from Everite Building Products a manufacturer of fibre cement products is used and presented. The results confirm that the sustained reliability of equipment depends on the efforts by the user to keep equipment reliable through methods supporting predictive and preventive maintenance.
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Dynamic capability theory as an input variable for supplier performance evaluation and selection

- Kganyago, N.J., Marnewick, A., Pretorius, J.H.C.

  • Authors: Kganyago, N.J. , Marnewick, A. , Pretorius, J.H.C.
  • Date: 2016
  • Subjects: Dynamic capability theory , Functional capability , Supplier performance evaluation criteria
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93263 , uj:20324 , Citation: Kganyago, N.J., Marnewick, A. & Pretorius, J.H.C. 2016. Dynamic capability theory as an input variable for supplier performance evaluation and selection.
  • Description: Abstract: Supplier performance evaluation and selection are two fundamental constituents of optimal sourcing decision making and are the main contributing factors to an effective supply chain and most importantly to the procurement process. Based on the literature and management experience the present research established that current evaluation criteria are intra‐organisational focused and give prominence to the use of supplier’s strategic capabilities. Little or no consideration is given to the influence of the changing business environment and the fact that there are many proposed evaluation criteria that exist today. To close the gaps the research introduces the theory of dynamic capability as an intrinsic criterion for supplier performance evaluation and also as the generic guideline to reduce the current multi performance evaluation criteria. The proposed model will empower the procurement practitioner with the criteria logic to identify the suppliers able to meet the demands of the changing business environment. This research is largely based on the literature and supply chain management experience to arrive at the conceptual model. The future research should validate the conceptual model through survey and case study research design methods to enable the conclusive generalisation of the results. The research contributes by conceptualising the generic model for supplier performance evaluation that combines supplier strategic capabilities and dynamic capability variables as the significant input variables for optimal sourcing decision making. The research also provides academics and the supply chain fraternity with enhanced knowledge of the literature of dynamic capability variables as generic criteria for supplier performance evaluation.
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Effects of culture on project management contributing to the success of managing culturally diverse engineering teams in a global environment

- Meyer, L.L., Pretorius, J.H.C., Pretorius, L.

Energy efficiency through the use of technology in South African industry

- Matlala, H.N., Marnewick, A., Pretorius, J.H.C.

Evaluation of savings from an underground fan replacement project

- De Canha, D., Pretorius, J.H.C., Laubscher, R., Van Rhyn, P.

  • Authors: De Canha, D. , Pretorius, J.H.C. , Laubscher, R. , Van Rhyn, P.
  • Date: 2016
  • Subjects: Measurement and verification , Energy efficiency , Underground ventilation
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/213676 , uj:21182 , De Canha, D. et al. 2016. Evaluation of savings from an underground fan replacement project.
  • Description: Abstract: The savings calculation methodology from a fan replacement project is presented in this paper. The fans replaced are part of the underground ventilation system in a platinum mine. Initially, 290 axial flow fans rated at 45kW were to be replaced with carbon fibre composite fans. According to the manufacturer, the carbon fibre construction allowed for an optimum blade shape which results in the carbon fibre fan being more energy efficient. However, after the first few fans were replaced, it was discovered that the mine’s blasting activities caused the carbon fibre fans to crack and eventually fail. Fortunately, the manufacturer was able to produce a steel fan with similar performance to that of the carbon composite fans and continue replacing old fans in the mine. The savings were independently verified according to the International Performance Measurement & Verification Protocol (IPMVP). This involved testing old and new fans in a BS848 test duct and comparing the old and new fans at various operating points on their fan curves and making adjustments for operating conditions such as air density underground vs at the test duct. It was found that the new fans saved 5kW on average, across a range of operating points.
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Evaluation of the impact of distributed synchronous generation on the stochastic estimation of financial costs of voltage sags

- Mbuli, N., Xezile, R., Pretorius, J.H.C., Sowa, P.

Impact of circuit-breaker maintenance on life-cycle cost comparison for fixed and magnetically controlled reactors

- Mbuli, Nhlanhla, Nkosi, Sphiwe, Mashego, Lehlohonolo, Pretorius, J.H.C.

Increasing the capacity of transmission lines via current uprating: an updated review of benefits, considerations and developments

- Ntuli, Mavula, Mbuli, Nhlanhla, Motsoeneng, Lethoko, Xezile, Ronald, Pretorius, J.H.C.

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