• Evaluation of Simulation-Based Optimization in Grafting Labor Allocation

      Masoud, Sara; Son, Young-Jun; Kubota, Chieri; Tronstad, Russell; Univ Arizona, Dept Syst & Ind Engn; Univ Arizona, Sch Plant Sci; Univ Arizona, Dept Agr & Resource Econ (AMER SOC AGRICULTURAL & BIOLOGICAL ENGINEERS, 2018)
      Vegetable grafting is a labor-intensive operation with many management decisions. Labor management and resource planning are critical allocations in grafting nurseries, yet optimization is challenging due to the dynamic nature of workers' performance in vegetable seedling propagation. To this end, we developed a simulation-based optimization framework for labor management to optimize labor allocation. This approach was evaluated by comparing its result with those suggested by selected domain experts (a plant scientist and a nursery manager). Furthermore, the simulation models were validated with a dataset from a developing tomato grafting company. Simulation-based optimization is demonstrated as an effective approach to find the optimal/near optimal labor allocation for horticultural nurseries, where discrete event simulation is used to represent the dynamics of the grafting work environment and meta-heuristics are used to devise optimal/near optimal resource allocation strategies. Results reveal that a potential annual savings between $2,510 (0.6%) and $97,388 (20%) can be achieved for a grafting facility of 6 million plants per year.
    • Unanticipated events, perceptions, and household labor allocation in Zimbabwe

      Josephson, Anna; Shively, Gerald E.; University of Arizona (Elsevier BV, 2021-05)
      This paper investigates labor allocation as a strategy for coping with unanticipated events. We evaluate household responses to unforeseen death and rainfall shocks in Zimbabwe, during a period in which many households were already stressed due to the country's long-term economic crisis. In this context, shocks compound existing stresses. Different types of shocks disparately affect household labor allocation. Household perceptions about the shocks experienced also shift labor use. Perceived rainfall shocks positively affect the share of labor allocated to migration-related activities and negatively affect the share of labor allocated to non-participation. © 2020 Elsevier Ltd