Structural analog

Structural analogs (structural analogue or simply analog) are models or representations that keep each other certain "structural similarity". It is used in engineering, chemistry, mathematics and other fields.

Despite the field diversity, all structural analog analysis use some level of abstraction to transform models in mathematical graphs, and detected structural analogies by algorithms. Example: for molecular structure comparison and classification operations, the compared compounds are modeled as a mathematical graph. Formally, when structures are represented by graphs, the concept of analog is related to a graph isomorphism.

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 structures (see illustration) if they are isomorphic graphs and have equivalent (mapped) lumped elements. In Electronics, methods based on fault models of structural analogs gain some acceptance in industry.