Saudi Arabia's industrial expansion is increasing the importance of electrical systems that can sustain production, protect critical process loads and accommodate frequent modification without creating hidden reliability weaknesses. This paper studies ETAP-enabled electrical system planning as a lifecycle engineering process for reliable and smart industrial facilities in Saudi Arabia. The emphasis differs from broad smart-grid planning: the review focuses on industrial network architecture, critical-load classification, redundancy, contingency operation, motor acceleration and reacceleration, load shedding, restoration, maintenance switching, equipment duty, and expansion planning. A structured narrative review of recent power-system reliability and maintenance literature, technical standards, Saudi energy-sector sources and ETAP engineering documentation was used to identify planning practices that can be translated into industrial decision-making. The review proposes a Reliability-Centred ETAP Planning (RCEP) framework in which a verified digital model is used to compare normal, maintenance, outage, disturbance and future-production scenarios before physical changes are approved. Particular attention is given to main-tie-main arrangements, transformer and feeder contingencies, process load priorities, large motor restart sequences, generator-supported operation, selective protection and the use of operational and maintenance data to keep the model current. The analysis shows that ETAP creates the greatest planning value when study cases are tied to explicit acceptance criteria such as retention of critical loads, acceptable voltage recovery, adequate interrupting duty, selective fault isolation and realistic restoration sequences. For Saudi industrial facilities, this approach supports safer capacity growth, stronger outage preparedness, more disciplined maintenance planning and better transfer of engineering knowledge from projects to operations. The paper concludes that smart industrial electrical planning should be treated as a controlled cycle of modelling, scenario testing, field validation and change management rather than as a one-time software study.