Electronic Theses and Dissertations (Masters)
Permanent URI for this collectionhttps://hdl.handle.net/10539/37972
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Item Assessment of Quality Management in Major Projects in the Mining Industry in Botswana(University of the Witwatersrand, Johannesburg, 2024) Pitswe, Odirile Boniface; Sunjka, BernadetteWhile project performance is generally evaluated in terms of schedule, cost and quality performance, guidelines for project quality management are lacking, (Steyn and Nicholas, 2008). The Botswana mining industry is faced with problems of engineering projects which don’t meet the expected outcomes and most of the problems emanate around quality management and quality defects. This research project involved the assessment of quality management in major engineering projects in the Botswana mining industry by evaluating the level of adoption and implementation of quality management systems in major engineering projects, identifying the major causes of project failure, and evaluating the effectiveness of quality management system as employed in major capital projects. The research was focused mainly on Debswana Diamond Mining company as the major mining house in the country, with an objective to assess the maturity level of the company’s quality management system (QMS) and identify opportunities for improvement. A mixed method approach was used which involved archival research and survey research, the results of which were triangulated to corroborate the findings and remove bias. Archival research was conducted using the company document repository to review project retrospect reports, (Lessons learnt reports) and identify problems experienced during the implementation of different projects. These were correlated with common causes of project failures as identified in the critical literature review and cross referenced against survey results to further confirm them. The results indicated that the maturity level of the Quality Management system is at level 4 (quantitatively managed), where processes are measured and controlled. Gaps were identified that if rectified would move the maturity to level 5 (optimizing), where the focus would now be on process improvement. The gaps are mainly around operationalisation, lower-level employees training on quality management, optimisation of shared resources especially subject matter experts like project engineers, key stakeholder management, involvement and participation from end users and operational teams. The study came up with the top five (5) major causes of project failure being: 1. Shared resources and subject matter experts get overstretched between different projects and end up neglecting quality assurance. 2. Poor stakeholder management. 3. Lack of stakeholder involvement and participation in the project. 4. Inexperienced project team. 5. Unclear statements of expected quality outcomes.Item A report on the investigation into factors that impact the replication of operational excellence programs across the global operations of a top global mining company: The Case of Rio Tinto(University of the Witwatersrand, Johannesburg, 2024) Tsomole, Moleboheng; Sunjka, BernadetteAchieving operational excellence in mining is fraught with challenges, including the lack of standardized procedures, misalignment with company strategy, and cultural disparities across global operations. This study investigates the strategies for efficient deployment of operational excellence programs, with a focus on Rio Tinto’s operational excellence framework, RTSPS (Rio Tinto Safe Production System). A mixed-methods approach was adopted, integrating qualitative data from semi-structured interviews with Rio Tinto managers and employees and an analysis of secondary data from company reports. This study combined deductive and inductive research approaches to provide a comprehensive exploration of operational excellence at Rio Tinto. The deductive approach involved testing specific hypotheses drawn from existing literature on operational excellence programs, such as the assumption that standardized systems like RTSPS would encounter difficulties in culturally diverse environments. Inductive reasoning complemented this by allowing themes and insights to emerge directly from empirical observations during interviews, thus offering an authentic view of the challenges and successes of RTSPS deployment. The qualitative component of the study was centered around 14 semi-structured interviews with key stakeholders across various regions, including operational excellence managers and improvement leads. These interviews were conducted virtually using platforms like Microsoft Teams and Zoom, enabling broad participation across geographically dispersed sites. The interview questions were meticulously crafted using Wengraf’s pyramid model, which starts with Critical Research Questions (CRQs) that are broken down into Theoretical Questions (TQs) and further refined into specific Interview Questions (IQs). This structured approach ensured that the interviews remained focused on uncovering detailed insights into operational challenges and strategic alignment. The questions were adapted to account for the contextual nuances of each participant's operational environment, and particular care was taken to avoid leading questions, thereby minimizing researcher bias.The analysis of data employed thematic coding, revealing key insights into behavioural adaptability, cultural diversity, and the influence of leadership on the adoption of standardized processes. Themes were generated from the qualitative data and cross-referenced with secondary data sources, including integrated annual reports that provided a broader organizational context and corroborated the findings. Secondary data analysis allowed for a deeper understanding of Rio Tinto’s strategic objectives and how these aligned or conflicted with ground-level practices. Using qualitative data from interviews with 14 participants, the research highlights key themes identified through thematic analysis, focusing on the complexities of implementing RTSPS across diverse cultural and operational landscapes. Sentiment analysis conducted via ATLAS.ti software provided additional insights into participants' attitudes and emotional responses, shaping the creation of a comprehensive codebook that guided systematic data analysis. The findings reveal that RTSPS faces significant deployment challenges, including the integration of a standardized system across culturally varied sites, a need for a more people-centric approach, and issues with communication, resource allocation, and adaptability. Participants with experience outside of Rio Tinto provided unique insights into alternative deployment strategies that could enhance replication and adaptability across different industries and operational settings. The study also identifies the foundational elements critical to RTSPS, such as standardized processes, robust training programs, and a centralized knowledge- sharing infrastructure. These components were highlighted as essential for fostering a culture of continuous improvement and ensuring successful replication across Rio Tinto’s operations. Rio Tinto's annual reports from 2018 to 2022 emphasize RTSPS's role in enhancing safety, efficiency, and sustainability, with impacts on the triple bottom line of people, planet, and profit. However, the challenges identified through this research include cultural integration, resource constraints, and the need for local adaptability, mirror broader issues documented in the literature on operational excellence in the 7 mining sector. The study concludes that while RTSPS holds significant potential, its success hinges on balancing standardization with the flexibility to accommodate local conditions and prioritizing employee engagement throughout the deployment process.Item Financial Evaluation of Implementing In-Pit Crushing and Conveying Systems for Waste on Open Pit Mines(University of the Witwatersrand, Johannesburg, 2024) Serepa, Ikaneng; Emwanu, B.The South African mining industry has faced mounting challenges, especially rising expenses that threaten profitability. These escalating costs, driven by various factors including operational expenses such as mining costs, are critical. The distribution of mining costs across activities within the production cycle is crucial, with hauling operations in open pit mines representing a significant portion, as noted by Paricheh et al (2017) at 49%. Due to the substantial economic impact of hauling expenses on mining expenditures, there's a strong incentive to streamline these operations to lower overall costs effectively. Current research highlights a noticeable transition in the mining sector towards embracing in-pit crushing and conveying (IPCC) systems in open pit mines, acclaimed as a cost-effective substitute for conventional truck and shovel (CTS) systems (Awuah-Offei et al, 2009). This research assessed both the integration and financial viability of implementing a waste IPCC system in the loading and hauling operations of an open pit mine. A mixed-methods approach, combining quantitative data from production records and costs with qualitative insights from expert interviews was used. The findings of this research indicate that while the IPCC system can be integrated, there remains a degree of reliance on the CTS system for material transportation from the pit to the IPCC system. For the CTS system, 55 rigid dump trucks (RDTs) are required, constituting 57% of the initial capital expenditure of R1.27 billion. Conversely, the IPCC system requires only 31 RDTs, accounting for 29% of the initial capital costs of R1.37 billion. However, despite the substantial reduction in RDTs, the IPCC system requires significant investment in a crusher and conveyor belt system for waste management, which constitutes 32% of its capital costs. Examination of the operating costs over the life of the mine indicates that there are no cost advantages associated with operating an IPCC system compared to the CTS system. Operating expenses for the IPCC system exceed those of the CTS system by 58%, predominantly driven by the operational costs of the crusher and belt system, contributing to 67% of the IPCC system's costs. The financial assessment results show a positive and acceptable net present value (NPV), internal rate of return (IRR), and payback period for both systems. Nevertheless, the CTS system exhibits superior financial performance, with a NPV of R7.45 billion, an IRR of 83.1%, and a shorter payback period of 1.2 years, and is recommended as a viable option for the mine.Item Measurement of combustion airf low into burners in coal fired plants(University of the Witwatersrand, Johannesburg, 2024) Manqele, Gladwell Sizwe; Schmitz, WalterThis research study is aimed at achieving accurate measurement of mass flow rates in large square industrial square ducts at Eskom’s boiler plants. For safe and efficient operation of Fossil Fuel Firing Boiler Plants, the utility has put in place the Fossil Fuel Firing Regulation Standard which requires that the Total Combustion Air flow be measured at exit from the air heaters, into the ducts. In this study, a sophisticated airflow measuring probe was acquired, herein the current study referred to the 14-hole Omniprobe. The accuracy was found to be within 5% in a free stream flow field. A Five-hole probe was calibrated in the free-stream wind tunnel. The calibration process enabled the derivation of the probe specific polynomials of Pitch, Yaw, Total Pressure, Static Pressure coefficients and velocity components. A prototype air duct was designed for the study to simulate air flow through square ducts with a 90⁰ bend as an abrupt flow disturbance. To achieve the objectives of the study, 6 planes were identified where air flow velocity profiles were generated using the equal area method. The modeling of the velocity profiles was conducted numerically, using CFD (Ansys Fluent), and experimental, using Pitot-static probe, Omniprobe, and a Five-hole probe. The mass flow rates as measured by the Pitot-static tube were found to be consistent at planes 1, 2, 5, and 6. The mass flow rate as calculated from the Pitot-static probe varied by 2.1% through the duct. This justified the selection of the Pitot-static probe as the reference for this study. The velocity profiles generated from the traverse measurements using the 14-hole Omniprobe showed an error in velocity measurements which are in the proximity of the wall. This can be attributed to the the wall effect. The mass flow rates of air calculated from the Five- hole probe measurements were found to be within 4% of the mass flow rate as calculated from the results of the reference probe in the 1st and 2nd planes upstream of the bend. After the 90⁰ flow disturbance bend, the accuracy drops to 13% at plane 5 and improved slightly at plane 6 to 11.7%. This is attributed to complex flow pattern at these planes. The study concludes that the Pitot-static tube remains the preferred instrument for use in measuring flow rates using the equal area method in large square ducts. The Five-hole probe can be applied where the flow field is not distorted in conjunction with CFD. The Omniprobe’s accuracy in measuring the velocity magnitude, and the angularity of the flow field was verified in an open stream wind tunnel. This study recommends exploring the use of an L-type 14-hole Omniprobe for application in large square industrial ducts.Item Distributed Electric Propulsion on a Joined-Wing Air-Taxi(University of the Witwatersrand, Johannesburg, 2024) Brand, Darren Mark; Schekman, S.Urban Air Mobility (UAM) is a form of aerial transportation within urban areas with the main intention of easing traffic congestion. Electric Vertical Take-off and Landing (EVTOL) air-taxis are currently in development, but no single configuration has been identified as superior for UAM. There is still scope for alternate designs to be explored. A major obstacle to successful UAM operations is the combination of high energy requirements for VTOL and low battery energy densities, thereby affecting operational aircraft range. Aerodynamic efficiency has been identified as a critical factor for achieving maximum flight range while electric battery technology is matured. It is proposed that an air-taxi which combines Distributed Electric Propulsion (DEP) with a joined-wing may achieve superior aerodynamic efficiency compared to other air-taxi designs. A joined-wing air-taxi capable of carrying four passengers and a pilot has been developed with four alternative DEP configurations. These aircraft are herein investigated and compared against one another. A computational approach was followed using STAR- CCM+ to evaluate the flow characteristics and forces around the aircraft for both climb and cruise conditions. It was found that a “Non-DEP” configuration with four proprotors can achieve up to 5% higher aerodynamic efficiency than a DEP variant. However, this configuration suffers with poor lifting capability at high angles of attack. The sensitivity of aerodynamic efficiency to changes in the number of proprotors and their spacing was seen to be negligible according to this investigation.