System Studies or System Engineering is the central activity for Electrical power system planning, engineering ,expansion, upgrade and configuration change,operational and functional Utilities of power system for electrical power supply.

It also Includes detailed investigations and on-site studies, Power Evacuation Studies, quality analysis, redesign and engineering, failure check related to power or Voltage curves, ICTs.

A vital part of it is the Load duration curve which illustrates the variation of a certain load in a downward form such that the greatest load is plotted in the left and the smallest one in the right. On the time axis, the time duration for which each certain load continues during the day is given.