{{Unreferenced, date=June 2019, bot=noref (GreenC bot) Functional analogs (or functional analogues) are entities (models, representations, etc.) that can be replaced, to fulfill the same function. When the entities in question are formally represented by

black box In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The te ...

es, the concept of ''analog'' is related to "same behavior": they take the same output sequence when submitted to the same input sequence.

Systems engineering

Analogical models are used in a method of representing a ‘ target system’ by another, more understandable or analysable system. Two systems have "analog functions" (see illustration) if the black box representation of both can be the same. electronics