| Attribute | A Rank | B Rank | C Rank |
| S—Safety and environmental effects | Failure would cause significant environmental issues in circumferential place | Failure would cause some safety and environmental issues in circumferential place | Failure would cause no safety or environmental issues in circumferential place |
| Q—Quality and revenue | Failure would cause abnormal product to be produced or significantly affect revenue | Failure would cause quality variation or affect revenue slightly | Failure would affect neither quality nor revenue |
| W—Working (operating) condition | 24 hours working | 7 to 14 hours working | irregular, working only |
| A—Delay factor (opportunity) condition | Failure would shut down the entire factory | Failure would shut down relevant system only | Stand-by unit available/more economical to wait for failure and then repair |
| P—Period (failure interval) | Frequent stops (every six months or more) | sporadic stops (approximately once a year) | Very hard for any stops (less than once a year) |
| M—maintainability | Repair time: 4 hours or more Repair cost: over 2400 USD | Repair time: 1 - 4 hours Repair cost: 400 - 2400 USD | Repair time: less than 1 hour Repair cost: less than 400 USD |