TUT DIGITAL OPEN REPOSITORY

Recent Submissions

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    Machine morphology in reconfigurable machine tools.
    (Elsevier, 2012-05-23) Mpofu, Khumbulani
    Machine morphology within the reconfigurable machine tool environment is considered in this article in a bid to address the configurations and reconfigurations that will be needed to meet the uncertain and unpredictable demands in the market. This paper proposes a hierarchical classification mechanism for machine structures, these structures derive from module combinations where symbology is utilized to represent the machines and these symbols can be used in the configuration process. Authors envisage this method to be relevant in the combinatorial problem reconfigurable environments face.
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    Concept development for reconfigurable bending press tools’ (RBPTs) modules using a novel methodology.IFAC Proceedings Volumes
    (Elsevier, 2012-05-22) Gwangwava, N.; Mpofu, K.; Tlale, N.; Yu, Y.
    This paper outlines the development of reconfiguration concepts for new optimized reconfigurable bending press tools (RBPTs) using a novel methodology. The researchers propose the reconfiguration concepts with the main objective of optimizing press brake utilization as determined by the set up bed length, multiple parts bent per set up, bending force, stroke height, bending technology, set up and r ramp up time, and number of strokes. The procedure for RBPT concept development include the construction of a first house of quality (HOQ1) based on the quality function deployment (QFD) technique. Research done by the authors identified two main objectives of RBPT design which are geometric transformation and productivity adjustment. The first can be further split into two reconfiguration categories, horizontal reconfigurability and vertical reconfigurability. These are used to derive reconfiguration needs for the RBPTs. Identification of the RBPT modules is done using the function driven object oriented (FUDOO) methodology. This involves identification of the primary function of a typical RBPT and cascading it down to sub functions and terminal functions subsequently. Reconfiguration concepts are then developed for each identified RBPT module. Length reconfiguration is proposed to extend or shorten the bed and ram span. This will be accomplished by introducing standard modules for the bed and ram beams optimally designed to withstand deflection during bending.
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    Review of the status of reconfigurable manufacturing systems (RMS) application in South Africa mining machinery industries.
    (Elsevier, 2014-01-01) Makinde, O.A.; Mpofu, K.; Popoola, A.P.I.
    Reconfigurable Manufacturing Systems (RMS) has been used extensively in different industries and companies to produce modularized, customized, flexible and scalable products. Due to the variations in the mining equipment users demand, dynamic nature and complexities in the mining manufacturing environment in terms of space available, kind of mining operations and the risks involved, RMS have been extensively used to produce different mining equipment product varieties of high adaptability, low repair cost and minimum maintenance cost in order to meet customers satisfaction. Further on, this paper explores on various literature review in relation to reconfigurable manufacturing system concepts, architectural design characteristics, control capabilities and its role in mining machinery industries, and the potential future of this RMS in South Africa mining machinery industries. Reconfigurable Manufacturing Systems has been used in mining machinery industries to manufacture Load Haul Dump (LHD) trucks, multiple drilling bits such as the tricone bits, screen mesh of different aperture sizes which has contributed immensely to the 15.3% GDP achieved by the manufacturing sector in South Africa. Global high mineral demand is a positive indicator for great future in this industry if RMS is fully harnessed, utilized and applied in this sector. Furthermore, a newly designed flexible, cheap, versatile and reconfigurable vibrating screen by Industrial Engineering Department, Tshwane University of Technology, Pretoria will also serve as a catalyst to catapult the mineral processing industries to its peak.
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    Comparison of weighted decision matrix, and analytical hierarchy process for CAD design of reconfigurable assembly fixture.
    (Elsevier, 2014-01-01) Olabanji, O. M.; Mpofu, K.
    Reconfigurable assembly fixtures are major components of a reconfigurable assembly system. They are precision components which require an intensive design process due to their usage and interaction with other components in the assembly system. Concept selection is a time consuming activity in the engineering design process, because it involves decision making and consideration of multiple factors. A computer aided design approach of four concepts was developed for a reconfigurable assembly fixture, based on functional requirements, cost, and manufacturability. The weighted decision matrix and analytical hierarchy process was used to compare these concepts. The decision criteria and evaluation technique used during this concept selection process is novel thus calling for its application in design of engineering components. The results of the two methods are presented graphically and the variations in the results obtained are used to judge the suitable method among both processes for the optimal design.
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    Inventory management framework to minimize supply and demand mismatch on a manufacturing organization.
    (Elsevier, 2015-01-01) Matsebatlela, M.G.; Mpofu, K.
    There is a problem of excessive inventory in a Manufacturing Company, situated in South Africa. In this study an Inventory Management Framework (IMF) was developed. Quantitative content analysis was used to collect data. Statistical tools were used to select the fiscal year with the vast data variation for data analysis for this study. The results reveal that uncertainties and lot sizing inventory results in excessive inventory and not having a collaborated and integrated Supply chain Management also results in a mismatch of supply and Demand. IMF is proposed in this paper to minimize the impact of the mismatch.