存貨管理在各大企業中皆是一項重要的議題，為了避免缺貨的情況發生或是囤積太多貨物導致成本過大，存貨管理能幫助管理者有效的進行補貨及出貨。在現實生活中，有些存貨會隨著時間的經過而產生損壞或腐敗，稱為易腐性商品，常見的有生鮮蔬果、魚肉類等，這類商品管理起來會比傳統存貨管理要困難一些。不同的蔬果有不同的生長特性，有些蔬果採收下後並不能馬上販售給消費者，必須先放置一段時間使蔬果達到最佳風味才可販售，因此對於單一農戶而言如何訂定採收販賣政策是相當重要的議題。除此之外，需求的起伏容易造成單一農戶無法精準了解到哪些是已知需求，為減少需求的不確定性會採用預售的方式來增加需求的確定性，並與相關加工廠簽約，將未售出的蔬果販售給加工廠進行二次加工，減少浪費。因此本研究根據農戶種植蔬果的情形建立一個多階段採收販賣的易腐性存貨模型，並加入預售的手法增加需求，以最大化利潤為目標，找出最佳的採收數量、採收時間以及各階段長度。研究結果發現，有預售手法能增加收入，但價格的訂定上須注意，若是預售之價格太低，雖能增加需求量，但以總體收入來說並無增加，而成本方面並無減少，會造成總利潤下降的情況。經由敏感度分析發現售價、最大種植量、單位持有成本、單位採收成本、需放置天數及腐敗率之形狀參數影響較大，若是想提高利潤可從這些參數項目進行調整，進而達到增加收入，減少成本的效果。

Fruit and vegetable are important food resource. People can buy the fresh fruit and vegetable in the supermarket. However, there are more and more farmers selling their agricultural product by themselves. Fresh fruit and vegetable would deteriorate as time goes by and the value of the fruit and vegetable would also decrease. However, each fruit and vegetable has its own growth characteristics and harvest season, and some fruit and vegetable have to be placed in the warehouse for a while, letting the flavor better. Besides, the demand change would let the famer miscalculate the demand. In order to decrease the uncertainty, presale is one of options can be used. Apart from this, the unsold fruit and vegetable usually are sold to the factory which processes the fruit and vegetable in to frozen ones. In this study, a multiple stages harvesting and selling with presale activity model is implemented to maximize the total profit and develop the inventory policy to find the optimal harvest quantity, harvest time and the length of time of each stage. Finally, a numerical example is provided to verify the appropriation of this model. In addition, the sensitivity analysis is conducted to determine the influences of different parameters with regard to total profit and the harvesting and selling policy. The result shows that selling price, maximum harvest quantity, unit holding cost, unit gathering cost, the number of days that need to place and the deteriorate parameter have significant effect on total profit.

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