Combing TOC and the replenishment model for optimizing deteriorating inventory management: A case study of the aerospace industry

Abstract

航空器可靠度與乘客安全有強烈的關聯

故在材料、零組件的要求標準皆高於其他產業。航空器的部分材料如漆、膠料等

其材料強度與價值隨時間遞減

加上不同航空器材料零件的特殊性

致使生產過程的缺料問題。但如為了避免缺料而過量存貨

遇到航空器構型變更

材料報廢將影響專案績效表現。本研究以兩階段存貨管理模型改善個案航空製造公司的存貨問題。先系統性地個案公司生產製造全貌

例如在航空製造業的議價能力、與生產製造相關的內部部門存貨管理制度。藉由限制理論方法

本研究診斷出個案公司物料管理的不良效應 (undesirable effects

UDEs) 根本原來自於內部各部門的物料管理方針不一所致。第二階段透過現況樹 (current reality tree

CRT)了解個案公司物料管理全貌

並邀請外部夥伴及內部各部門協調

避免強調部門績效反而降低整體專案獲利的現象。透過四種生產模型的模擬分析結果

個案公司得在不同議價能力與價格基礎下

達到最佳化專案績效目標。

As there are strong and positive correlations between the reliability of aircrafts and passenger safety

the requirement on quality and choices of materials and components remains a top priority compared to all other industries. Some aircraft materials

such as paint

glue

rubber

and composites

deteriorate in quality and value over time

resulting in stock shortages. In addition

high inventory levels of materials are the main characteristic of the aircraft manufacturing industry due to design change requests and the variety and complexity of the materials. This study adopts a two-stage process to improve inventory management for the case company in the aerospace industry. The first stage systematically assesses issues such as bargaining power and determines the relevance and interactive influence among sectors related to inventory management. By using the theory of constraints (TOC)

this study further diagnoses the undesirable effects (UDEs) of material management systems and identifies root problems or inconsistent material management actions. Via UDEs

the second stage constructs a current reality tree (CRT) to realize a company’s material management objectives and requirements and to figure out what actions it must take to meet these objectives. This study also explores four scenarios that would benefit from such improvement. The ultimate goal in the future is for vendors to be able to distribute profits according to the corresponding situation.