Table 1 Classification of ESR
From: Weakness Ranking Method for Subsystems of Heavy-Duty Machine Tools Based on FMECA Information
Category | Description | ESR Score | Trapezoidal fuzzy number ESR Score |
|---|---|---|---|
Class I (Disastrous) | Major failure occurs; loses specified function; causes major safety accidents, casualties, and significant damage | 10, 9 | \(\widetilde{R}_{1}\)= (8, 9, 10, 10) |
Class II (Deadly) | Severe damage; loses specified function; no casualties occurs | 8, 7 | \(\widetilde{R}_{2}\) = (6, 7, 8, 9) |
Class III (Crisis) | Specified function degrades; loses partial performance | 6, 5, 4 | \(\widetilde{R}_{3}\) = (3, 4, 6, 7) |
Class IV (Mild) | Minor failure occurs; specified function degrades; acceptable performance | 3, 2, 1 | \(\widetilde{R}_{4}\) = (1, 1, 3, 4) |