Browsing by Author "Maturana, Sergio"

Now showing 1 - 4 of 4
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    A multi-objective approach for supporting wine grape harvest operations
    (2020) Varas, Mauricio; Basso, Franco; Maturana, Sergio; Osorio, David; Pezoa, Raúl
    In this paper, we present a novel multi-objective mixed-integer linear programming model to support wine grape harvesting. The proposed model considers the opposing nature of operational cost minimization and grape quality maximization, subject to several constraints, such as grape requirements and routing decisions. Based on the operations of a winery we worked with, we develop a negotiation protocol that can lead to an agreed final harvest schedule. The protocol includes an initial Pareto optimal solution obtained through the augmented weighted Tchebycheff method. Then, the solutions are presented to the two decision-makers and, if no agreement is reached, we conduct an iterative process, which includes finding Pareto optimal solutions in a neighborhood using the augmented ∊ -constraint method. Finally, we choose, within this set, the solution following a substitution rate criteria. We illustrate our procedure using an educational example.
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    Managing premium wines using an (s- 1 , s) inventory policy: a heuristic solution approach
    (2019) Varas, Mauricio; Basso, Franco; Lüer-Villagra, Armin; Mac Cawley, Alejandro; Maturana, Sergio
    Operations research models are increasingly being used to support decision making in the wine industry. However, they have not yet been used to support inventory management decisions. In this paper, we develop a heuristic procedure for managing the stock of premium wines motivated by the operations of a small export-focused winery we worked with. Following an (s - 1; s) inventory policy, we assume that the decision maker aims to minimize the steady-state expected values of work in process, overage, and underage costs. The developed heuristic is as follows. First, we approximate the dynamics of the labeling process by a group scheduling policy to obtain the mean delays for each labeled product. Then, we address the problem of setting the inventory positions for the whole product portfolio by solving one newsvendor-type problem for each end-product. We provide some theoretical insights, a numerical example, and we analyze the accuracy of our procedure.
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    Measuring efficiency in the Chilean wine industry: a robust DEA approach
    (2021) Varas, Mauricio; Basso, Franco; Maturana, Sergio; Pezoa, Raúl; Weyler, Marcelo
    The Chilean wine industry has been quite innovative in terms of winemaking and trading. Yet, to survive in this competitive industry, wine managers should be aware of the relevance of monitoring their performance. In this paper, we assess how the five wineries listed on the Santiago Stock Exchange of Chile are efficient while using their critical resources for making profits. Particularly, we apply data envelopment analysis (DEA) to benchmark and rank these wineries’ technical efficiency based on four inputs and one output. We use data gathered from consolidated financial statements that are prepared using estimates, judgements, and assumptions. To account for some level of ex-post adjustments in data, we evaluate these wineries’ relative efficiency using a robust DEA model, which deals with ambiguous, imprecise, and uncertain input-output parameters. We analyse several levels of variability suitable for this data source, and we evaluate how changing the conservatism level affects technical efficiency and the rankings of the wineries. We also conduct a comparison between the five Chilean wineries and nine others from the New World. As the main conclusion, we found that Chilean wineries keep their efficiency level when including international firms in the analysis.
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    Measuring efficiency in the Chilean wine industry: A robust DEA approach
    (2020) Varas, Mauricio; Basso, Franco; Maturana, Sergio; Pezoa, Raúl; Weyler, Marcelo
    The Chilean wine industry has been quite innovative in terms of winemaking and trading. Yet, to survive in this competitive industry, wine managers should be aware of the relevance of monitoring their performance. In thispaper, we assess how the five wineries listed on the Santiago Stock Exchange of Chile are efficient while using their critical resources for making profits. Particularly, we apply data envelopment analysis (DEA) to benchmark and rank these wineries’ technical efficiency based on four inputs and one output. We use data gathered from consolidated financial statements that are prepared using estimates, judgments, and assumptions. To account for some level of ex-post adjustments in data, we evaluate these wineries’ relative efficiency using a robust DEA model, which deals with ambiguous, imprecise, and uncertain input-output parameters. We analyze several levels of variability suitable for this data source, and we evaluate how changing the conservatism level affects technical efficiency and the rankings of the wineries. We also conduct a comparison between the five Chilean wineries and nine others from the New World. As the main conclusion, we found that Chilean wineries keep their efficiency level when including international firms in the analysis.

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