Preventive maintenance planning: case study of air conditioner testing room

Abstract

This research presents an approach to applying preventive maintenance principles to mitigate the issue of unexpected test interruptions in an air conditioning test chamber, primarily caused by steam system malfunctions. These malfunctions occurred with an average frequency of 0.67 times per month, resulting in a testing room downtime of 8 days per incident. The study began with identifying the root causes through maintenance history and in-depth analysis using Why-Why Analysis. It was determined that the steam system malfunctions were due to improper steam bypass operations of operators and the inappropriate replacement scheduling of critical components of the steam system. To fix these issues, the study implemented new procedures and standards for steam system bypass operations and established a preventive maintenance plan. This plan included replacing the Reduce Valve and Motor Valve after 920 days and 950 days of usage, respectively, based on survival function analysis using the Weibull distribution. Following the implementation of these corrective measures, there were no further unexpected test interruptions due to steam system failures over a monitoring period of reliability function with the Weibull distribution model. Consequently, this led to a 100% reduction in unexpected test interruptions in an air conditioning test chamber. This study concludes that the corrective actions, including the establishment of new operational standards and equipment replacement schedules, successfully achieved the objectives and can be applied to similar issues in other contexts.