MIL-STD-1629-RevA - Barringer and Associates, Inc.

MIL-STD-1629Aaction or series of actions by an operator, followed by a check or crossreference either to instruments, control devices, circuit breakers, orcombinations thereof. This procedure is followed until a satisfactorycourse of action is determined.5.8 Compensating provisions. The compensating provisions,either design provisions or operator actions, which circumvent or mitigatethe effect of the failure shall be identified and evaluated. This stepis required to record the true behavior of the item in the presence ofan internal malfunction or failure.5.8.1 Design provisions. Compensating provisions which aref-tures of the design at any indenture level that will nullify theeffects of a malfunction or failure, control, or deactivate systern”itemsto halt generation or propagation of failure effects, or activate backupor standby items or systems shall be described. Design compensatingprovisions include:a. Redundant items that allow continued and safe operation.b. Safety or relief devices such as monitoring or alarmprovisions which permit effective operation orlimits damage.c. Alternative modes of operation such as backup orstandby items or systems.5.8.2 Operator actions. Compensating provisions which requireoperator action to circumvent or mitigate the effect of the postulatedfailure shall be described. The compensating provision that best satisfiesthe indication(s) observed by an operator when the failure occurs shallbe determined. This may require the investigation of an interfacesystem LO determine the most correct operator action(s) . The consequencesof any probable incorrect action(s) by the operator in response to anabnormal indication should be considered an(i tl~eeffects recorded.5.9 Severity classification. A severity classificationcategory (see 4.4.3) shall be assigned to each failure mode and itemaccording to the failure effect. The effect on the functional conditionof the item under analysis caused by the loss or degradation of outputshall be identified so the failure mode effec~ Wi].1 be properly ca~egorizet].For lower levels of indenture W}lere effects ,J[~}li&i]erindenture levelsare unknown, a failure’s effect on the indenture level under analysisshall be described by the severity classification categories.5.10 Remarks. Any pertinent remi~rks pertaining to and clarifyingany other column in the worksheet line shall be noted. Notes regardingrecommendations for design improvements shall be recorded al~d*TASK !01101-724 November 1980———-. — — _— —. ————._=__.__——-—-———-———.————— ————.—.