Document :

ITU-T SG05  (Study Period 2025)  Contribution  637

Title :

Best practice for introduction of Resistibility Requirements based on Field Failure Analysis

Date :

2026-10-06

Source :

Cisco Systems, Inc. (United States)

AI/Question :

Q2/5

Meeting :

2026-10-20

Observation :

To be verified by TSB

Access :

Restricted to TIES users [ITU-T]

Abstract :

. Data-Driven Standard Updates: Major standards bodies (ITU-T, Telcordia, IEEE, IEC) dynamically update overvoltage and overcurrent resistibility requirements when statistical A field return rate of 1-2% or higher for critical functions is typically considered sufficient to trigger formal RCA and standards review.
. Sequential Root Cause Analysis (RCA) Methodology: Physical root cause analysis progresses from non-destructive techniques (visual, X-ray) to destructive testing (decapsulation, SEM/EDX) to conclusively determine failure origins.
. Distinct Damage Signatures: Components such as MOVs, TVS diodes, and PCB traces exhibit unique physical and chemical damage patterns that differentiate environmental overstress (e.g., lightning) from installation faults (e.g., poor grounding).
. Misattribution of Field Failures: Case studies reveal that equipment damage initially attributed to environmental power surges is frequently caused by improper installation, such as ground loops or incorrect mounting hardware.
. Targeted Corrective Actions: When failures stem from user or installation errors, manufacturers favor improving installation manuals, implementing Poka-Yoke designs, and issuing field notices rather than needlessly increasing product test resistibility standards.