Saudi Arabia’s industrial and commercial facilities are becoming increasingly electrically complex. Manufacturing expansion, data centres, petrochemical integration, metro systems, healthcare campuses, tourism developments and renewable generation all increase the demand for safe, reliable and flexible power systems. Electrical Transient Analyser Programme based studies provide a practical engineering platform for converting drawings, asset data and operating assumptions into coordinated planning decisions. This paper reviews the possible support of the ETAP based power system analysis to smart grid planning in Saudi industrial and commercial facilities through the integration of load flow, short circuit, protection coordination, motor starting, harmonic, arc flash, reliability and renewable interconnection studies. We used a structured narrative review methodology to examine sources published between 2020 and 2025, including peer-reviewed smart grid literature, power system study research, utility reports, technical standards and ETAP-oriented engineering references. The review finds ETAP to be most valuable when it is not used merely as calculation software, but as a digital planning environment that links the design of facilities, operational reliability, safety compliance, asset loading and future distributed energy integration. The most impactful planning applications for Saudi facilities are transformer and cable sizing validation under high cooling loads, fault level and breaker duty verification, relay coordination to avoid unnecessary shutdowns, arc flash exposure estimation, power quality assessment with variable speed drives and PV, battery and microgrid options prior to capital deployment. The paper proposes a phased ETAP enabled smart grid planning framework aligned with Vision 2030, industrial localisation and grid reliability objectives. It concludes that robust modelling governance, verified field data and periodic model updates are critical if ETAP studies are to underpin resilient, safer and more efficient Saudi facilities.