IMPLEMENTING A STRUCTURED FAILURE ANALYSIS SYSTEM

摘要

BAGASSE reclaimer failures are traceable from 1991 with multiple failures in 2005 and 2006 prompting a formal investigation into the root cause of failure. The techniques selected for use were Failure Modes and Effects Criticality Analysis (FMECA) and Root Cause Failure Analysis (RCFA). These are common and powerful tools applied by reliability and maintenance engineers involved in the identification of potential hazards, their criticality, and the ultimate cause of failure. The initial analysis failed due its lack of structured methodology and inability to look beyond the accepted cause. This root cause was thought to be simply the introduction of tramp material with little consideration of other possible causes. Following this first analysis, current control was installed on the drive and Key Performance Indicators (KPIs) placed upon fuel suppliers to ensure quality fuel. Twenty months later another failure occurred, instigating a comprehensive and structured analysis with the application of FMECA and RCFA. A number of possible failure modes were identified including inadequate systems control, manufacturing flaws, slip-ring failure, and transverse impact loading of the drive chain. Failure after implementation of motor control and KPIs is not attributed to a single root cause but to a combination of poor design, manufacturing defects and flawed maintenance procedures. The welded link chain was replaced with a bolted link configuration in conjunction with routine inspection and maintenance. Chain life is anticipated to return to design life, with a $60 000 cost saving in the 2008/2009 budget. This initiative has faced cultural resistance but with persistence has reaped encouraging results. Rewards extend beyond fiscal integrity with a positive shift in maintenance strategy and attitude.