捷運系統可靠度及風險評估研究

Abstract

某國快捷系統自2009年7月1日至2010年4月30日期間約10個月內共發生181次延誤事件，本研究依據可靠度工程原理及故障樹分析方法估算此期間內該快捷系統系統的可靠度與可用度，並特別針對車輛、號誌、通訊、供電、月台門與軌道等六個次系統，估算它們的平均故障時間、可靠度及可用度，另應用「風險矩陣方法」進行系統與次系統內各零組件的風險評估與分類。研究結果顯示，某國快捷系統自2010年2月至2010年4月估算的系統可用度，均高於設定之目標值0.99，可推論此系統應已持續趨向穩定狀態。研究結果亦顯示，於此段期間內之車輛、號誌及通訊三個次系統可靠度較其他另三個次系統低很多，因此相關工作人員需設法提高此三個次系統的可靠度；其中，通訊次系統中之「非同步傳輸(Asynchronous Transfer Mode，簡稱ATM)網路」與號誌次系統之「自動列車保護(Automatic Train Protection，簡稱ATP)軟體」皆曾發生過延誤一小時以上之事件，屬於風險矩陣中無法接受之高風險項目，建議相關工作人員應確實按照標準作業程序操作或維修相關重要設備，以有效降低風險，避免類似事故再度發生。

The rapid transit system occurred 181 delay incidents during its operation period from July 1, 2009 to April 30, 2010. It spanned for about 10 months. The present thesis applies reliability engineering theories and Fault Tree Analysis method to find the system reliability and availability during this period. The mean time to failure (MTTF), reliabilities and availabilities of its six major subsystems namely vehicle, signal, communication, power supply & distribution, platform door, and rail subsystems are also investigated. Risk matrix is employed to assess and classify individual risks of components within the system and subsystems. The result indicates monthly availabilities of the system from February 1, 2010 to April 30, 2010 are higher than the objective value (0.99). It is concluded that this system is approaching its steady-state availability gradually.The result also indicates reliabilities of the vehicle, signal, and communication subsystems are lower than those of the other three subsystems. Reliabilities of these three subsystems have to be enhanced accordingly. The result also shows that both the Asynchronous Transfer Mode (ATM) network of the communication subsystem and the Automatic Train Protection (ATP) software of the signal subsystem have caused delay incidents for more than one hour. They belong to high risk items in the risk matrix and deserve more attention when maintenance is carried out. To reduce the risk and avoid similar incidents, engineers should operate and maintain vital equipment of these kinds carefully based on standard operation procedures.