A comprehensive qualitative and quantitative assessment of harvesting and other sugarcane supply chain disruptions within the Eston Mill supply area.

Abstract

The Eston Mill, which was established in 1994, is the newest in the KwaZulu-Natal sugar belt. Like for most other mills, it can be argued that there are inefficiencies in the supply chain due to systemic issues, which reduce optimum performance. The literature study involved a review of the factors which cause inconsistencies in sugarcane supply chains and the strategies implemented for improvement. This research study involved five main aims. First, a novice qualitative diagnostic analysis of the Eston sugarcane system, to identify a range of systemic issues and one pertinent problem, involving pay-weekends and subsequent labour absenteeism, was isolated for further investigation. This was conducted through explorative interviews and network analysis approaches. Secondly, based on the information from the diagnostic analysis, a model that predicts and quantifies the factors which influence daily crush rate disruptions at Eston, was developed, validated and verified. Thirdly, the extent of the pay-weekend problem area was systematically estimated in terms of frequency, variability and predictability. Fourthly, the cost of cutter absenteeism was conservatively quantified, based on two factors, namely, sugar recovery and mill operational costs. Lastly, a case study was carried out, which involved the feasibility of a mechanical harvesting system, to mitigate the impacts of labour absenteeism. The model involved the calibration of parameters for mill maintenance and operational stops, rainfall events and days in the week when slow crush rates occurred. The model captures approximately 64% of the variation observed in daily crush rates. Subsequent to the development of the model, additional cane supply disruptions, caused by cutter absenteeism, were also investigated. It was statistically verified that a significantly detectable degree of labour absenteeism occurs immediately after pay-weekends. There has been a general increased trend in cutter absenteeism from about 2007 until 2010. An economic analysis estimated the costs associated with cutter absenteeism to be approximately R1.3 million per season, for the Eston region. The alternative harvesting system case-study solution, was found to be risky. However, acquiring second-hand equipment, which was available on the market, is estimated to make the solution more feasible. Based on a literature search, this research is considered to be the most comprehensive analyses of sugarcane supply consistency at mill-scale worldwide. The model developed can be utilized to critically evaluate different sugarcane milling areas and could potentially make significant contributions to commercial sugarcane operations. The effectiveness of the model is dependent on usage in other milling areas, as well as other industries. In addition, the specific labour absenteeism coefficients for each season can possibly be investigated using other industries as well.