Distribution systems are usually the main areas where power outages occur. Electricrnpower interruptions in the capital city of Ethiopia,i.e. Addis Ababa, are usualrnproblems. Even there are situations that electric power interruption occurs severalrntimes a day.rnThis thesis tries to identify the causes of power interruptions for the Kotebe distributionrnsystem and the vulnerability of the existing components. It is a componentbasedrnfailure analysis on a selected feeder of the distribution system. It is selectedrnconsidering the total annual frequency of interruptions for each feeder of the distributionrnsystem. Feeder 6 of the Kotebe substation is the most frequently interruptedrnline. The existing conditions of the components on the feeder are inspected. Distributionrnpoles, conductors, insulators, transformers, protection and other auxiliaryrndevices are the inspected components. The probable effect of the most frequentrncauses of interruptions identified in the distribution on the poor distribution componentsrnis studied.rnInterruption during operation and maintenance is the common cause identified inrnthe distribution. But this is through the order of the maintenance workers of thernutility. Sudden faults are usually due to weather influences. It accounts for 48.66%rnof the total known faults excluding interruption due to operation. The vulnerabilityrnto failure of the existing distribution poles is identified through modelling therndistribution poles, gravitational force of tilted poles and weather influence by COMSOLrnsoftware. Decay depth of wooden poles considering the selected area weatherrncondition is studied using TimberLife software, and its effect for failure is simulatedrnusing COMSOL. Poles will deflect upto 3.050 and 1.7490 with and without consideringrndecay depth at the worst condition of a certain weather influence, respectively.rnPoles resilience condition is also identified by analyzing deflection and stress on theirrnsurface.rnMany of the existing distribution transformers are working overloaded. The loss ofrnlife of distribution transformers and their vulnerability is studied using the IEEErnstandard (C57.19-1995) guidelines. The hot spot temperature, ageing accelerationrnfactor, and percent loss of life of each transformer are calculated. 83 of 157 transformersrnare expected to sustain below the IEEE standard expected life (i.e., 20.55rnyears). The effect of lightning considering soil resistivity of the area is also studiedrnby modelling the feeder 6 of Kotebe distribution system using Matlab/Simulink.rnMetal Oxide Varistor(MOV) Surge arresters with grounding resistance above 25Î© would have higher surge magnitude that could damage the transformers and surgernarresters.