備用品庫存水準最佳化達成設定設備運轉效能之研究 - 以玻璃基板製造業物料搬運設備為例

Abstract

本研究以玻璃基板製造廠物料運輸輸送系統作為研究的個案，運用個案公司的維修紀錄與備品採購之歷史資料，並篩選物料搬運系統之關鍵零件集合。對於物料搬運系統之關鍵零件集合中的零件，運用維修紀錄估算零件故障個數與故障間隔時間之歷史資料，建立該關鍵零件故障間隔時間的機率密度函數。運用關鍵零件故障間隔時間的機率密度函數、維修時間與採購前置時間，建立物料搬運系統的模擬模式。採取窮舉法測試不同關鍵零件備品庫存數量的組合，以模擬模式測試在5年之內物料搬運系統的故障維修時間超過8小時的次數。由窮舉法所測試的備品庫存數量組合，選擇運用最小成本達成「5年之內物料搬運系統的故障維修時間超過8小時的次數不超過5次」的基準，作為最佳的備品庫存數量組合。系統模擬的決策架構與研究結果，在備用品庫存水準的決定，可以提供個案公司訂定設備維護備品庫存水準的參考。

This study employed the material handling facilities in a TFT-LCD factory as a case study. We screened the set of critical parts for the material handling system from the historical data from the procurement and maintenance logs. Then, we conduct fitting analysis on the number of parts used for maintenance, the time between failures of the part to get the probability distribution of failure events for the critical parts. We formulated the corresponding simulation model for the material handling system based on the results of fitting analysis on the part consumption, the time between failures. Then, we used an enumeration approach to test different combinations of inventory levels of spare parts using the simulations, recorded the number of events in which the breakdown of the system lasts more than 8 hours (in short, BMT8). We pick the best combination of inventory levels of spare parts that meets the required conditions BMT8 is no more than 5 times with the minimum inventory holding cost. The framework and results of the proposed system simulation could serve an important support and reference on the decision of inventory levels of spare parts for the case company.