felfunktion

Felfunktion is a term that appears in a limited set of technical writings to denote a function that describes how faults arise, propagate, or manifest within a system. It is not a standard term in established dictionaries, and its meaning tends to vary by discipline. In many contexts scholars would interpret it as a mathematical or computational model of malfunction rather than a physical component.

Etymology and usage: The name derives from the German Fehl- (fault) and Funktion (function). The form felfunktion is uncommon in formal German, where Fehlfunktion is used for malfunction; some authors coin felfunktion as a portable or neutral label for a fault-revealing mapping.

Applications and modeling: In reliability engineering and systems theory, a felfunktion may be used to describe the relation between a system state and the observed fault signal. It can be deterministic, mapping states to fault indicators, or stochastic, assigning probabilities to fault events. In control or diagnostic settings, the function helps formalize how faults develop and affect outputs.

Example: Consider a simple device with two states: normal (0) and fault (1). A felfunktion F could map the control input and current state to an output fault indicator, such as F(0, normal) = 0 and F(0, fault) = 1, with possible probabilistic extensions F(t) giving the likelihood of fault at time t given exposure and age.

See also: Fehlfunktion; Reliability engineering; Fault tree analysis; State estimation; Failure modes and effects analysis.

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