Preventive & Predictive Maintenance Flashcards

Which failure pattern, described in the Nowlan and Heap studies, shows a high early failure rate that decreases to a constant rate?

Answer: Infant mortality

Infant mortality patterns show many early failures from defects or installation errors, then a steady low rate.

Given that many failures follow an infant mortality pattern, what risk is associated with overly frequent intrusive PM?

Answer: It can introduce new defects through disassembly and reassembly

Each intrusive task can reset the asset to its vulnerable early-life period by introducing errors.

Motor circuit analysis or insulation resistance testing with a megohmmeter is primarily used to detect what?

Answer: Deteriorating winding insulation

Megger testing measures insulation resistance to identify winding degradation before a motor fails.

Which is the best source of data for adjusting PM frequencies over time?

Answer: Equipment failure history and inspection findings recorded in the CMMS

Historical failure and findings data show whether intervals are too long or too short.

Ultrasonic thickness testing is most useful in building systems for which purpose?

Answer: Measuring pipe and tank wall loss from corrosion

Ultrasonic thickness gauges measure remaining wall thickness, revealing corrosion or erosion.

What is a key advantage of a route-based PM program for building rounds?

Answer: Technicians complete multiple inspections efficiently in a logical sequence

Routes group nearby tasks to minimize travel time and improve consistency.

Which equipment should generally receive priority when allocating limited PdM resources?

Answer: Critical assets whose failure has high safety, operational, or cost consequences

Criticality ranking directs monitoring effort where failures would hurt most.