Order assignment and two-stage integrated scheduling in fruit and vegetable supply chains

Fruit and vegetable supply chains require tight integration due to freshness-keeping requirements during the post-harvest, production, and distribution stages. This paper addresses the scheduling problem of a two-stage flow shop in the fruit and vegetable supply chain involving procurement, production, distribution, and order assignment. The supply chain consists of contract growers, processors, and demand points. Growers and processors maintain limited capacity. Growers have processing lines to sort and grade fruits and vegetables, which are then shipped to processors for further processing. The first stage of the problem involves determining the production and distribution schedules of growers to processors. The second stage concerns assigning demand points to processors, scheduling production at processors, and distributing from processors to demand points. This paper considers its two sub-problems and proposes a mixed-integer linear programming problem: growers’ and processors’ production and distribution scheduling with order assignment. Also, we present two respective strongly polynomial algorithms for solving the two sub-problems. Besides, we develop a two-phase heuristic algorithm for the integrated problem by solving sub-problems together. We conduct computational experiments to justify the proposed algorithms and integration value. Computational results reveal that the proposed algorithms outperform the CPLEX on large-scale problem instances. Finally, we analyze the impacts of waste reduction, unit processing time and cost, and inbound and outbound shipping rates on supply chain performance, along with managerial insights.