A MULTI-PERIOD NEWSVENDOR PROBLEM WITH PRE‐SEASON EXTENSION UNDER FUZZY DEMAND

Abstract

This paper proposes a fuzzy multi‐period newsvendor model with pre‐season extension for innovative products. The demand of the product is represented by fuzzy numbers with triangular membership function. The holding and shortage cost parameters are considered as imprecise and also represented by triangular fuzzy numbers. As the selling season draws closer, suppliers lead times shortens and thus production costs increase. In contrast, caused by the oncoming selling season, demand fuzziness decreases and more accurate demand forecasts can be maintained that lead to lower overage/underage costs. The objective of the model is to find the best order period and the best order quantity that will minimize the fuzzy expected total cost. The model is experimented with an illustrative example and supported by sensitivity analyses. Santrauka Straipsnyje pasiūlytas neraiškusis keliu laikotarpiu pardavimo modelis, papildytas paruošiamuoju laikotarpiu inovatyviems produktams. Produkto paklausa apibūdinama neraiškiaisiais skaičiais, aprašytais trikampe priklausomumo funkcija. Turto ir sanaudu parametrai laikomi netiksliais ir taip pat apibūdinami trikampe priklausomumo funkcija aprašytais neraiškiaisiais skaičiais. Kai pardavimo laikotarpis priarteja, tiekimo laikas trumpeja, o gaminio kaina išauga. Priešingai, del praeinančio pardavimo laikotarpio paklausos neapibrežtumas sumažeja ir galima tiksliau prognozuoti paklausa, o tai padeda sumažinti išlaidas del gaminiu pertekliaus ar trūkumo. Šio modelio tikslas – rasti geriausia užsakymo laika ir geriausia užsakymo kieki, kurie padetu sumažinti visu numatomu sanaudu neapibrežtuma. Pateikiamas modelio taikymo pavyzdys ir modelio jautrumo analize.