Respecting the historical development of the power grid throughout Europe, which started intensively after World War II, it is evident that a large number of overhead power lines have been in operation for many years. As overhead power lines age, as well as due to operating conditions and climate parameters, the reliability of the system operation and the safety of power supply to network users decrease. Asset management in the power grid primarily involves planning the refurbishment of individual network units (elements), whereby it is necessary to determine investment priorities well in order to maintain a uniform and satisfactory overall condition of overhead power lines. With this aim, the idea of determining investment priorities according to the risk of currently existing assets was conceived. Investment priorities in assets can be determined by creating a model that would encompass the condition of each individual element of the overhead power line and determine its risk, as well as the risk of individual sections as a whole. In this sense, this paper considers the methodology of overhead power line refurbishment planning based on the principles of a modern approach to asset management, i.e. AIM/CBRM methodology (Asset Investment Management - AIM; Condition Based Risk Management - CBRM). It provides a common framework of definitions, principles and calculation methodologies, and has been adopted by all distribution system operators in the United Kingdom for asset risk assessment, prediction and regulatory reporting. The paper presents relevant calculations and their comparison for two common methods of overhead power line refurbishment, i.e. the percentage replacement option and the targeted intervention option, on a hypothetical set of overhead power lines that constitute input data for calculating asset risk and required costs by applying the aforementioned methodology.