Transportation planning model for the supply of fresh tomatoes in South Africa
A transportation planning model was developed based on mode of transport, vehicle maintenance and production costs against revenue from tomato of different maturity stages supplied by different growers in a commercial supply network. Fruit quality of different maturities, transport and storage conditions were integrated into the model, and quality constraints implemented to allow the selection of fruit that meets the requirements of different markets. The objective function was to maximize profits from the quantity of fruit demanded while meeting the quality constraints of different markets. Fruit firmness, hue angle and ascorbic acid content were selected as the quality attributes to be built into the model. The model was run under two configurations, with one configuration being strict on enforcing the quality constraints and the other configuration relaxing the quality constraints, while allowing the selection of fruit of each maturity stage. Different quantities of fruit were selected, based on each transport and storage temperature regime. In a typical scenario, the model was shown to improve the profits of commercial growers by over ZAR 8000 per truckload of fruit, while ensuring that fruit quality requirements of consumers were met. The relaxed model configuration can be implemented in cases where fruit is sent to the open markets that are less strict on quality. The model is potentially beneficial from a transportation planning perspective and its implementation will improve tomato grower's profits, reduce food waste and allow competitive integration of emerging growers into the commercial growers' network.
Cherono, K. and Workneh, T.S. (2019). Transportation planning model for the supply of fresh tomatoes in South Africa. Acta Hortic. 1258, 63-72
optimal supply parameters, multi-criteria optimization, fruit quality