DSCF without SPFM-target value

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DSCF without SPFM-target value

Explanation:

A search will be made for dangerous safety-critical failures (DSCF), which have no SPFM-target value (ISO 26262) assigned.

Note:

  • A DSCF (Dangerous Safety Critical Failure) is a failure, which is anchored at a function identified as a safety goal (see properties dialog) and has a safety level (SIL/ASIL) not equal to QM (Quality Management).
  • SPFM (ISO 26262) = Single Point Fault Metric [%]

Example:


Abbreviations
  • ASIL = Automotive safety integrity level
  • BF = Base failure of a base function
  • BFn = Base function of a base structure element
  • BSE = Base structure element
  • Cl Prc = Classification for process characteristic
  • Cl Prd = Classification for product characteristic
  • Cl Req = Classification for requirement
  • CM = Control method
  • DA = Detection action
  • DC = Diagnostic coverage
  • DSCF = Dangerous safety critical failure
  • Er Det = Error detection
  • Er Resp = Error response
  • F = Failure
  • FIT = Failure in time
  • Fn = Function
  • FSM = Functional safety management
  • IE = Inspection equipment
  • LF = Latent fault
  • LFM = Latent fault metric
  • OC = Operating condition
  • PA = Preventive action
  • PE = Process element
  • PFH = Probability of failure per Hour
  • PMHF = Probabilistic metric for random hardware failures
  • PrcC = Process characteristic
  • PrdC = Product characteristic
  • QM = Quality method
  • QR = Quality rule
  • Req = Requirement
  • RMR = Risk Matrix Ranking
  • RP = Reaction plan
  • SE = Structure element
  • SE ErDet = Structure element for error detections
  • SE ErResp = Structure element for error responses
  • SFF = Safe failure fraction
  • SG = Safety Goal
  • SIL = Safety integrity level
  • SM = Organisational-SE for “safety mechanisms”
  • SPF = Single point fault
  • SPFM = Single point fault metric
  • TF = Top failure of a top function
  • TFn = Top function at root element
  • TS = Test sample


079_SE

  • This structure consists of three system elements, each of which have three functions and of those each one failure. The functions that contain safety goals have this info in brackets in the function name. The IQ-Software automatically identifies a function as a safety goal if at least one failure anchored below this function has a SIL/ASIL value unequal to QM.
  • The aim of this Quality Rule is to find failures that have safety goals assigned. Furthermore, these failures must have different safety level to that of QM and have no SPFM-target value assigned.
  • With the display option setting “Functional Safety parameters” active for the structure list, it is possible to see which failures have different safety level to QM and which of these failures do not have a SPFM-target value assigned.

Search result: Search results

Four of the failures in the above example have safety goals. One of them has the safety level QM and therefore is not a hit. Of the three remaining, two have SPFM-target values. As such, there is one hit in this search: TF2.

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