Quantile forecast optimal combination to enhance safety stock estimation

Trapero Arenas, Juan Ramon and Cardos, Manuel and Kourentzes, Nikolaos (2019) Quantile forecast optimal combination to enhance safety stock estimation. International Journal of Forecasting, 35 (1). pp. 239-250. ISSN 0169-2070

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The safety stock calculation requires a measure of the forecast error uncertainty. Such errors are usually assumed to be Gaussian iid (independently and identically distributed). However, deviations from iid lead to a deterioration in the performance of the supply chain. Recent research has shown that, contrary to theoretical approaches, empirical techniques that do not rely on the aforementioned assumptions can enhance the calculation of safety stocks. In particular, GARCH models cope with time-varying heterocedastic forecast error, and kernel density estimation does not need to rely on a determined distribution. However, if the forecast errors are time-varying heterocedastic and do not follow a determined distribution, the previous approaches are inadequate. We overcome this by proposing an optimal combination of the empirical methods that minimizes the asymmetric piecewise linear loss function, also known as the tick loss. The results show that combining quantile forecasts yields safety stocks with a lower cost. The methodology is illustrated with simulations and real data experiments for different lead times.

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Journal Article
Journal or Publication Title:
International Journal of Forecasting
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This is the author’s version of a work that was accepted for publication in International Journal of Forecasting. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in International Journal of Forecasting, 35, 1, 2019 DOI: 10.1016/j.ijforecast.2018.05.009
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Deposited On:
21 May 2018 13:06
Last Modified:
29 Sep 2023 01:36