利用市場需求預測調整在需求拉動補貨策略中之存貨緩衝—於晶圓製造業之應用

Abstract

半導體產業中產品生命週期短、產品生產前置時間長，適用半導體產業供應鏈的補貨策略是值得研究的議題。需求拉動補貨策略配合緩衝管理在許多研究中均表現出其績效優於傳統(s, S)、(s, Q)、(R, S)、(R, s, S)等補貨策略。緩衝管理是一種顏色管理，以倉庫中的存貨數量與緩衝目標的差距將庫存狀態分為紅黃綠三種顏色；分別代表存貨偏低、適中、偏高。根據庫存狀態的不同調整緩衝存貨目標增加或減少訂貨數量。但在半導體體產業中產品單價昂貴，無法配合市場趨勢補貨造成存貨過多的情形，會影響公司的營運績效。本研究根據半導體產業實際情形提出一個結合預測資訊與緩衝管理的補貨策略，針對下游願意對上游分享滾動式預測資訊的良性互動關係，利用預測資訊訂定存貨緩衝目標，較能夠配合市場需求的變動趨勢，提升補貨策略的績效。本研究分別利用實際案例資料與模擬資料驗證此種補貨策略之可行性與有效性。研究結果顯示，與傳統需求拉動結合緩衝管理的補貨策略相比，本研究所提出的方法，在下游願意提供市場預測資訊且預測有一定準確度的情況下，確實能夠在不影響服務水準的條件下，大幅降的平均存貨。

Theory of Constraint suggests the use of demand-pull replenishment policy with buffer management to ménage inventory. This policy has been demonstrated to be more effective in practice than those traditional replenishment policies such as (s, S), (s, Q), (R, S), (R, s, S). Since the replenishment lead time of semiconductor products is long and their demand changes rapidly, customers are willing to share their demand forecasts with upstream partners, such as wafer foundries, to reduce their inventory. This study proposed a method to incorporate demand forecasts to improve the effectiveness of using demand-pull replenishment policy along with buffer management to manage inventory. This study used real data provided by a wafer foundry in Taiwan as well as simulated data, respectively, to demonstrate the effectiveness and efficiency of the proposed approach. The results showed that compared with the traditional demand-pull replenishment policy, the proposed approach can reduce the average inventory while not decreasing the desired service level. The more reliable of the demand forecasts, the more effective results the proposed approach can deliver.