Browsing by Author "Darley-Waddilove, Joshua Ian"

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    Allocating commodity volumes in the citrus export cold chain: A case for the Port of Durban
    (Stellenbosch : Stellenbosch University, 2021-03) Darley-Waddilove, Joshua Ian; Goedhals-Gerber, Leila Louise; Thiart, Jeanette; Stellenbosch University. Faculty of Economic and Management Sciences. Dept. of Logistics
    ENGLISH ABSTRACT: In this study, the feasibility of using “forced” allocation as a mechanism to aide in alleviating capacity challenges at the Port of Durban is explored and insights on the impact of reallocation to the citrus export cold chain is provided. The use of the mechanism is explored by limiting the allowable citrus throughput that may be handled at the Port of Durban for varying through put scenarios, and using allocation techniques to allocate the allowable citrus throughput amongst the competing production regions. An allocation model framework is formulated to optimally allocate the total citrus export volumes in a season to each of the South African ports that export citrus, taking into account the allowable port throughput constraint at the Port of Durban. The allocation model framework is modelled as a minimum cost transport problem and is solved using linear programming. The results of the 2019 actual export season for citrus exports is compared to the results of the 2019 forecasted export season to determine if there is a single suitable allocation technique that can be used to allocate the allowable port throughput to the production regions in the allocation model framework for future export seasons. The results show that there is no single suitable allocation technique, and so allocations on forecasted citrus export volumes must be done on a case-by-case basis. A possible export plan for the 2021 forecasted export season is calculated using the allocation model framework for each scenario to provide a baseline export plan for the different allowable throughput scenario’s at the Port of Durban. The forecasted citrus export volumes are forecasted using a four period double moving average forecasting model. The feasibility of using “forced” allocation as mechanism to alleviate capacity challenges faced at the Port of Durban is assessed on two criteria, namely the availability of theoretical excess capacity at the alternate ports to handle the citrus volumes reallocated and the change in total transport cost to the citrus export cold chain. The assessment of the criteria, and the analysis of the results, indicate that the use of “forced” allocation is feasible in the majority of, but not in all of the port throughput scenarios. Even though it is feasible in terms of the available capacity, there is, however, an increased transport cost to the citrus export cold chain in the majority of the scenario’s analysed. This additional transport cost must be weighed up against the cost of congestion and lost time, and will have to be absorbed by the citrus export cold chain. Eventhough there is an increase in transport cost, which can affect the total citrus export cold chain by as much as +35.2% (in the worst case scenario), the mechanism is deemed feasible as the impact of the increased transport cost is a relative measure that will have a varying impact amongst the different stakeholders of the citrus export cold chain and so each stakeholder will have to decide independently if it is feasible to them. The study achieved its primary aim of alleviating capacity pressures at the Port of Durban by reallocating citrus volumes to all South African ports that can handle citrus under different levels of available capacity at the Port of Durban. Therefore, “forced” allocation is deemed a good alternative solution to the current congested situation.