1. Priority of recommended actions shall be determined
CFT/GCFT shall determine if further action is necessary after the initial identifying failure mode, effect and control including ranking of occurrence and detection. What the team shall concentrate is the failure mode that was ranked with the highest severity.
(1) In case 9 or 10 of severity, it shall be made sure that the risk deals with current design control or recommended actions (as described in FMEA).
(2) With regard to the failure mode having 8 or below of severity, the cause that has the highest rank of Occurrence or Detection shall be considered. Examining the identified information and determining the tackling method, the best method to determine the priority of the best actions for risk reduction for both (HIAMS) Gr. and customer shall be determined.
(3) 2. Recommended actions
(4) 2.1 For design actions consider using following:
(5) • Results of Design DOE (Design of Experiments) or reliability testing
(6) • Design analysis (reliability, structural or physics of failure) that would confirm that the solution is effective and does not introduce new potential failure modes
(7) • Drawing, schematics, or model to confirm physical change of targeted feature
(8) • Results from a design review
(9) • Changes to a given Engineering Standards or Design Guidelines
(10) • Reliability analysis results
(11) 2.2 In general, prevention actions (i.e., reducing the occurrence) are preferable to detection actions. An example of this is the use of proven design standard or best practice rather than product verification/validation after design freeze.
(12) The intent of recommended actions is to improve the design. Identifying these actions should consider reducing rankings in the following order: severity, occurrence, and detection.
(13) (1) To Reduce Severity (S) Ranking: Only a design revision can bring about a reduction in the severity ranking.
(14) High severity rankings can sometimes be reduced by making design revisions that compensate or mitigate the resultant severity of failure.
(15) For example: The requirement for a tire is to “retain applied air pressure under use”. The severity of the effect of the failure mode “rapid loss of air pressure” would be lower for a “run flat” tire.
(2) To Reduce Detection (D) Ranking: A reduction in the occurrence ranking can be effected by removing or controlling one or more of causes or mechanism of failure mode through a design revision.
Examples of concrete method:
• Error proof the design to eliminate the failure mode
• Revised design geometry and tolerance
• Revised design to lower the stresses or replace weak (high failure probability) components
•Add redundancy
• Revised material specification
(3) To Reduce Detection (D) Ranking: The preferred method is the use of error/mistake proofing. An increase in design validation/verification actions should result in a reduction of detection ranking only. In some cases, a design change to a specific part may be required to increase the likelihood of detection (i.e., reduce the detection ranking). Additionally, the following should be considered:
• Design of Experiments (particularly when multiple or interactive causes of a failure mode are present)
• Revised test plan
3. In case there is no recommended actions
If the assessment leads to no recommended actions for specific failure mode/cause/control combination, indicate this by entering “None” in this column. Enter a rationale if “None” is entered, especially in case of high severity.