Doctoral Degrees (Industrial Engineering)

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    A carbon mapping framework for the international distribution of fresh fruit
    (Stellenbosch : Stellenbosch University, 2023, 2023-03) Du Plessis, Martin Johannes; Van Eeden, Joubert; Goedhals-Gerber, Leila Louise; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: The emissions impact of distributing goods such as fresh fruit is increasingly attracting attention due to the heightened awareness of greenhouse gas (GHG) emissions. However, despite the importance of freight logistics, assessing how transportation, handling, and storage of goods produce emissions, is largely an underdeveloped field. This is predominantly the result of a lack of practical industry guidance. The distribution of fresh fruit exported from South Africa is one such process that requires a standardised and accurate method to determine GHG emissions. The primary aim of this dissertation was to develop a carbon mapping framework and emission intensity factors for the international distribution (transportation, handling, and storage) of fresh fruit from South Africa. The framework and factors should enable any stakeholder with reasonable knowledge to calculate the carbon footprint (kg CO2e/kg of fruit) and the total emissions (kg CO2e) produced by the various distribution activities from a packing facility up until the port of discharge. To achieve this primary aim, several research objectives (ROs) were satisfied using a well-defined mixed methods research approach. This mixed methods approach was ideal since it enabled the triangulation of quantitative and qualitative input data. The sources of data included literature, observations, emission intensity factors developed from primary data collected from industry, distribution chain diagrams, semi-structured interviews with subject matter experts (SMEs), collaboration with the fruit export industry, and the iterative application of the framework to validate typical distribution scenarios by which fresh fruit is exported. The large number of different inputs enabled constant and continuous verification of each part of the research, thereby ensuring the subsequent results' validity and research rigour. Apart from the validation of each part of the research by SMEs, the validity of the research was also confirmed by the five journal articles included in the dissertation document. The application of the developed carbon mapping framework and associated emission intensity factors showed that the carbon footprint for scenarios where deep-sea ocean transport is used as mode for the main carriage varies between 0.31 and 0.84 kg CO2e/kg of fruit. If air transportation is used as mode for the main carriage, the carbon footprint can be up to 11.35 kg CO2e/kg of fruit. These results are, however, scenario-specific and depend on the transportation mode, the number of activities performed during the pre-carriage phase, the duration of storage, the packaging configuration of fruit, the transportation distances, and the origin-destination pair, amongst other things. However, it is certain that the distribution of fresh fruit, like many other commodities, emits a significant amount of emissions, necessitating urgent decarbonisation. The carbon mapping framework and emission intensity factors developed in this research not only set a standard for the South African fruit export industry to estimate distribution emissions but also provides other commodity groups with guidance to develop a similar emission accounting standard. With global freight volumes growing due to globalisation and economic progress, practical tools such as this framework are now more important than ever for understanding the emission impact of logistical decisions and freight distribution.
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    Socio-technical experiments for sustainable energy technology innovation: a gendered perspective
    (Stellenbosch : Stellenbosch University, 2023-03) Van der Merwe, Stefani; De Kock, Imke Hanlu; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: In sub-Saharan Africa, energy poverty is not eradicated at a sufficient pace, therefore exacerbating energy insecurity. The impact of this restricted access to sustainable energy sources is more severe in vulnerable urban poor areas. Moreover, most households in these contexts suffer from a lack of any formal energy system to meet the (growing) urban population’s energy needs. Historically, many efforts have been made to counter energy insecurity. However, such efforts have largely ignored the (newfound) statistically significant correlation between gender and energy consumption patterns – specifically the correlation between the gender of the household head and the energy consumption of the home, and the role that gender plays in energy technology innovations. An alternative approach to energy innovations is therefore needed. This is especially relevant in the sub-Saharan African context, as most households are female-headed, but with decision-making responsibilities being mainly male-oriented. It is therefore imperative that energy technology innovations and solutions are co-designed and developed using a bottom-up approach, as social dynamics play a more important role than what may be perceived. This study views energy as a complex socio-technical system and thus argues that innovations at the gender–energy–technology nexus should be approached as multidisciplinary, interdisciplinary and transdisciplinary. Principles are borrowed from fields outside of engineering, such as social science, energy justice, socio-economics, gender studies and systems thinking. First, a systematic literature study is conducted to determine the state of the art (i.e. current state) of gendered energy technology innovations. This structured literature study employs the multivocal literature review approach as well as the PRISMA methodology. Gaps are identified and subsequently, a gap analysis literature study is conducted employing the methodology of a conceptual literature study. Next, the intended research product’s requirement specifications are stipulated to guide the structured process of solution development in this study. Applicable and appropriate theoretical constructs are also identified from the literature (e.g., the Energy Value Chain, Technology Development Processes, the Quadruple Helix Model, the energy justice framework, and Scaling Archetypes), informed by the guidance provided through the requirement specifications. A framework for Gendered Energy Technology Innovations (GETI framework) is then developed to facilitate and support the processes of designing, developing, and implementing gendered energy technology innovations (i.e. energy technologies that specifically have a gendered component). Additionally, the GETI framework is specifically developed to be used for socio-technical experimentation in urban poor environments in sub-Saharan Africa. The user of the GETI framework is identified as being a ‘knowledge intermediary’, i.e. a stakeholder that coordinates stakeholders from various spheres of society. The GETI framework is evaluated by: (i) Verification through semistructured subject-matter expert interviews; and (ii) Validation through case study application. Finally, recommendations for future work are provided and it is concluded that there are opportunities for using the GETI framework as a structured and systematic guide to be used for socio-technical experiments in urban poor environments in SSA.
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    A framework for developing remote patient management systems in South Africa.
    (Stellenbosch : Stellenbosch University, 2023-03) Barimwotubiri, Ruyobeza; Sara (Saartjie), Grobbelaar; Adele, Botha; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: Digital health technologies have for several years been expected to reduce the skyrocketing health related costs and the care burden on traditional healthcare systems. One type of digital health technology expected to significantly improve the quality of, and access to, primary healthcare services is Remote Patient Management Systems. Based on a combination of rapid advances in body sensors, information and communication technologies, as well as artificial intelligence, it is hoped that remote patient management tools and systems (RPMTS) will improve the efficiency and quality of traditional healthcare systems. However, the adoption of the above systems has been extremely slow, especially in developing countries, where they ought to have made the greatest positive impact. Scholars have offered several valuable, insightful, and pertinent contributions to address the above challenge. However, in most cases, these contributions are atomistic, transitory, nonspatial, and dispersed. This study proposes an integrated process framework to guide and support developers in improving RPMTS adoption and scaling. The framework is developed based on existing literature on technology adoption and scaling theories and frameworks, as well as insights from industry practitioners, and integrated through design science research (DSR) methodology. As part of the DSR methodology, proposed novel and restructured concepts and frameworks were evaluated through a statistical survey and semi-structured interviews. Furthermore, a modified, two-round Delphi study was conducted to evaluate the framework's relevance and utility. The study's conclusions and recommendations emanated from the barriers identified in the extant literature and were confirmed through the field studies conducted in this research project. These include defining adoption success and failure ahead of RPMTS' design and development, interweaving adoption and scaling requirements into system development and project management activities, and the need for continuous monitoring and evaluation across RPMTS lifecycle phases.
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    Evaluating sectoral innovation system functional performance in the additive manufacturing sector: cemented tungsten carbides case studies
    (Stellenbosch : Stellenbosch University, 2023-03) Mc Clelland, Michelle; Grobbelaar, Sara Susanna; Sacks, Natasha; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: It is well known that innovation and manufacturing have traditionally played a vital role in the economic growth of developing countries. A ceramic widely used in manufacturing is cemented tungsten carbide, also known as hardmetal. Hardmetals are known for their significant ability to withstand extreme conditions and are used to manufacture abrasives, bearings and cutting tools as it is more heat-resistant than diamonds. Although traditional hardmetal manufacturing techniques are successful globally, several additive manufacturing (AM) technologies are being investigated as complementary manufacturing processes due to the design benefits the technologies offer. For society and the South African hardmetal industry to benefit from AM technology, the research studies on these technologies must be translated into valuable and innovative products, processes and services that are diffused and integrated into industry and the economy. Although the South African government has developed several national strategies relevant to the South African hardmetal industry, the effectiveness of the governmental support of the industry has not yet been explored through the innovation system framework. This study proposes an analysis framework to study the evolution of innovation systems. The framework, based on the literature on the innovation system framework, the method of event history analysis and the realist evaluation perspective’s logic structure, are developed through the design science research (DSR) methodology. Its objective is to guide the obtainment and documentation of the influential events in a system’s development and to structure the analysis of the event data according to context, intervention, mechanism, and outcome logic. The framework may therefore aid innovation scholars and system analysts to successfully analyse and compare the evolution of innovation systems and gain practical insights into possible support mechanisms. Moreover, the framework is shown to address and successfully overcome shortcomings of existing frameworks in the literature. As part of the DSR methodology, this study presents four instantiations of the framework to four novel case studies. These instantiations demonstrate the frameworks’ comprehensiveness in gaining case-specific insights. The framework’s ability to generalise across case levels is also validated as the insights from four cases could be compared. Additionally, this study presents the derivation of a survey instrument from the framework’s functional elements. Finally, this study presents the analysed survey response data from 70% of the South African AM enterprises, along with policy support suggestions, derived from the case insights, to support the enterprises’ development. Conclusions derive from the case studies and survey include that the South African AM enterprises are still relatively young and typically employ less than 50 people. Value-added enterprises also dominate the industry, although several international service bureaus exist. Furthermore, the enterprises struggle to identify laws and regulations that support AM technology, and startup enterprises struggle to build sufficient knowledge networks. Finally, this study suggests six important process mechanisms for translating manufacturing inventions into valuable and innovative products and processes that are diffused and integrated into industry.
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    Development of a blockchain-based traceability architecture for mapping object-related supply chain events
    (Stellenbosch : Stellenbosch University, 2023-02) Dietrich, Fabian Tobias; Louw, Louis; Daniel, Palm; Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering.
    ENGLISH ABSTRACT: Supply chains have evolved into dynamic, interconnected supply networks, which increases the complexity of achieving end-to-end traceability of object flows and their experienced events. With its capability to ensure a secure, transparent, and immutable environment without relying on a trusted third party, the emerging blockchain technology shows strong potential to enable end-to-end traceability in such complex multitiered supply networks. However, as the dissertation’s systematic literature review reveals, the currently available blockchain-based traceability solutions lack the ability to map object-related supply chain events holistically, which involves mapping objects’ creation and deletion, aggregation and disaggregation, transformation, and transaction. Therefore, this dissertation proposes a novel blockchain-based traceability architecture that integrates governance and token concepts to overcome the limitations of existing architectures. While the governance concept manages the supply chain structure on an application level, the token concept includes all functions to conduct object-related supply chain events. For this to be possible, this dissertation’s token concept introduces token ‘blueprints’, which allow clients to group tokens into different types, where tokens of the same type are non-fungible. Furthermore, blueprints can include minting conditions, which are, for example, necessary when mapping assembly or delivery processes. In addition, the token concept contains logic for reflecting all conducted object-related events in an integrated token history. This ultimately leads to end-to-end traceability of tokens and their physical or abstract representatives on the blockchain. For validation purposes, this dissertation implements the architecture’s components and their update and request relationships in code and proves its applicability based on the Ethereum blockchain. Finally, this dissertation provides a scenario-based evaluation based on two industrial case studies from a manufacturing and logistics perspective to validate the architecture’s capabilities when applied in real-world industrial settings. The proposed blockchain-based traceability architecture thus covers all object-related supply chain events derived from the two industrial case studies and therefore proves its general-purpose end-to-end traceability capabilities of object flows.