| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 92 === The automated material handling system (AMHS) is an important role in a 300mm semiconductor wafer manufacturing system. Peters & Yang[Yang & Peters，1997；Peters & Yang，1997]pointed that an AMHS with turntables and/or shortcuts appropriately can reduce the heavy traffic flow problem, and improve the AMHS performance much in a semiconductor plant. They devoted themselves to study the benefit for adding the shortcuts in a spine configuration of semiconductor fabrication. They addressed that the material handling costs should be reduced, due to the decrease of total transportation distance, as the number of shortcuts increases. However, the adding turntables and/or shortcuts to an AMHS cannot produce any products. Can one quantitatively estimate the benefit of the installation of turntables and/or shortcuts, or tell how soon the installation cost be paid back?
The main purpose of this study intends to answer the investor how much profit one can obtain, or how soon one can recover the cost if one adds turntables and/or shortcuts to an AMHS. This study has three phases. In phase one, based on Little’s law, we develop a method to quantitatively count how many pieces of product to be extra produced, or how many pieces of WIP to be reduced in the production line, because of adding shortcuts. In phase II, based on Hou [2001], a TOC profit and TOC inventory cost estimation methods are derived. The extra profit or the saving cost can be calculated. And the cost recover time can thus be estimated. In phase Ⅲ, for the purpose of demonstration, we adopt eM-Plant, a simulation tool, to simulate an AMHS with/without shortcuts in a 300mm fabrication plant. The methods developed in phases one and two are used. And the benefit of the installation of shortcuts is thus estimated quantitatively.
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