Search:
linked failures that are anchored to the same function
Explanation:
A search will be made for pairs of linked failures that are anchored at the same function
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
- The above image has five structure elements, each of which contains one function which in turn has multiple anchored failures.
- The hot-click icon to the left of the failure indicates that all failures are connected in one or more failure nets. To see failure net connections, use either the Failure Net Editor or Failure Graph Editor. The following image shows the failure net links.
- With the correct Display options set in the Failure Net Editor, it is possible to see which failures are anchored at which functions. This makes it possible to see which pairs of linked failures are anchored at the same function.
Search result:
Using the structure list and the failure net images above, it is possible to deduce that the following are not hits: Fn1, Fn2 and Fn3 do not have linked failures in the failure net that build pairs at the same function. The IQ-objects circled in red do not count as pairs. Pairs of failures can only be horizontally and not vertically determined at the same level!
The same does not apply to the failures at Fn4 and Fn5. Here you can see that failures F7 and F9, both anchored at Fn4, are pairs. Furthermore, F10 with F11 and F10 with F12 are pairs.
F13 and F11 are not pairs, despite being are anchored to the same function Fn5 (see ). Inbetween these failures is the failure F8, which belongs to a different function Fn4.
This Quality Rule, therefore, delivers 5 hits: F7, F9, F10, F11 and F12.