Predictive Maintenance Techniques Flashcards
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Read the first 7 Predictive Maintenance Techniques flashcards as text
In a PdM alarm management system, which alarm level typically requires the machine to be removed from service at the next planned opportunity rather than immediately?
Answer: Alert (caution) alarm
An alert (caution) alarm indicates a developing condition that warrants increased monitoring and scheduling repair at the next maintenance window, while a danger alarm requires immediate action.
When establishing PdM inspection route frequencies, the primary factor that should drive how often a machine is monitored is:
Answer: The P-F interval (time between a detectable fault and functional failure)
The P-F interval defines the detection window available; inspection frequency must be set at no more than half the P-F interval to reliably catch faults before functional failure.
When calculating the return on investment (ROI) of a PdM program, which cost category represents the avoided costs credited to the program?
Answer: Unplanned downtime, secondary damage, and emergency repair costs prevented
PdM ROI is driven by avoided costs — primarily unplanned downtime, collateral damage from run-to-failure, and expensive emergency repairs that planned interventions prevent.
In condition monitoring, a 'false positive' (false alarm) occurs when:
Answer: Monitoring data indicates a problem that does not actually exist
A false positive (Type I error) is an alarm triggered when the equipment is actually healthy, wasting maintenance resources and eroding technician confidence in the PdM program.
Trend analysis in predictive maintenance involves plotting condition indicator values over time primarily to:
Answer: Project when a parameter will reach an alarm threshold to schedule proactive repair
Trending projects the trajectory of a deteriorating parameter forward in time, allowing planners to estimate the remaining useful life and schedule repair before the danger level is reached.
Which statistical analysis technique is commonly used in PdM programs to identify the most critical failure modes to monitor, based on severity, occurrence, and detectability?
Answer: Failure Mode Effects and Criticality Analysis (FMECA)
FMECA ranks failure modes by Risk Priority Number (RPN = Severity × Occurrence × Detectability), helping prioritize which failure modes most need predictive monitoring coverage.
When a PdM route data collector shows a vibration reading that is three times higher than the last measurement taken two weeks ago on the same bearing, the best immediate next step is to:
Answer: Re-measure the point to confirm the reading before raising an alarm
A sudden large change should first be verified with a repeat measurement to rule out sensor coupling errors, transducer faults, or data entry mistakes before triggering a work order.