The present unreliable and erratic power supply is a pointer to the fact that there is a great need for fault evaluation and reliability studies of electric power system in Nigeria. The recent blackout in the country has grounded many activities and has destroyed many industrial processes. Also, the power industries face a lot of problems. Some of the highest priority issues being generation of sufficient power, urgent clearance of faults, adequate protection and increase reliability of the system. The Nigerian power problem resulted to incessant planned, forced and unplanned outages. It has resulted to erratic and unreliable supply of electricity in the country. It has reduced productivity and has increased unemployment rate in the country to over 40 million. It has led many of the youths in the country to crime. It has led to the deaths of many innocent people in the country. Hence, an analytical method is developed to assess the dynamic- reliability of the distribution system in the country, as well as its effects on the economy and security of the country.