Electrical Transient Analyzer Program (ETAP) is an electrical network modeling and simulation software tool used by power systems engineers to create an "electrical digital twin" and analyze electrical power system dynamics,transients and protection.

ETAP is a full spectrum analytical engineering software developed by Operation Technology Inc. (OTI). The software specializing in the analysis, simulation, monitoring, control, optimization, and automation of electrical power systems. ETAP software offers the most comprehensive and integrated suite of power system enterprise solution that spans from modeling to operation.