The average absolute error of outage model with peak demand 1-9 MW is shown in Table X. The results show that the outage cost model by G-bell membership function has the least percentage of absolute error with 16.12% and 8.62% for peak demand 1-9 MW and 4-9 MW, respectively. In order to study the benefits from construction 115/22 kV substation, the outage cost model with peak demand 4-9 MW is considered to determine the outage cost which used as the parameter in the economic assessment.