Search:
Linked failures with inversely connected function links
Explanation:
A search will be made for pairs of linked failures whose corresponding functions are linked in opposing directions.
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
- Each of the five structure elements of this example has one function (
) and one failure (
) assigned. - To view which functions are linked with which failures in the structure list, active the hot-click icons in the Display options (“Function net” and “Failure net”). How the links look in more detail can be viewed in the Function Net and Failure Net Editors, which is important for this Quality Rule.
- The hot-click icons to the left of the functions and failures indicate that these IQ objects are connected in one or more function or failure net. The following images show individually how they are connected.
- 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 functions linked in the opposite direction. It is important to check for errors here where the function net objects are linked in the opposite direction to that of the failure net.
Failure net links
Function net links
Search result: 
The above images show that the corresponding functions of failure pair F1 and F3 are linked in the opposite direction to that of the failures. The same can be said about the failure pair F5 and F7. On the other hand, the functions of failure pair F5 and F9 are linked in the same direction.
The hits from this example are: F1, F3, F5 and F7.