A study of cane supply benefits associated with ad hoc mechanical harvesting to mitigate cutter absenteeism

Abstract

The Eston Sugar Mill is the newest in the South African KwaZulu-Natal sugar belt. Like most other mills, it can be argued that there are inefficiencies in the supply chain due to systematic issues, which reduce optimum performance. It was alleged that mill processes are slowed, or stopped, on Sundays, Mondays, as well as some Tuesdays and Wednesdays, due to pay-weekends, because of the associated cutter absenteeism. This increases the length of the milling season (LOMS), increases milling costs and reduces the average cane quality for the season. Data on cane deliveries to the Eston Mill, over a period of five seasons, were analysed to study the magnitude of the problem. It was statistically verified that cane shortages occur immediately after payweekends and it was conservatively estimated that cutter absenteeism occurs between 25–29 days per season, which increases the LOMS by six to ten days. The associated cost of this problem equated to an average of US$159,500 (approximately EUR120,000) per milling season. In this paper, an alternative harvesting system scenario is suggested, assuming that mechanical harvesters be used after a pay-weekend, to mitigate the impacts of cutter shortages. However, the solution is calculated to be risky. When the cost of new equipment was considered, only two of the five seasons were able to justify the associated costs.