The goal of the article lies in development of a methodical approach to identification of expediency of transfer of the production enterprise equipment maintenance to outsourcing, which would consider specific features of the servicing production and degree of its influence upon basic production processes. The existing approaches to identification of expediency of transfer of functions and business processes of an enterprise to outsourcing were systemised by the classification feature of the method type, on the basis of which the approach is built and advantages and shortcomings of each of them are marked out. The article establishes that this grouping could be used as a set of alternatives on justification of introduction of outsourcing into the practice. In accordance with the goal of the study the article builds a methodical approach to identification of expediency of transfer of the production enterprise equipment maintenance, which is based on a comparative analysis of integral ratio of efficiency of own maintenance service and efficiency of maintenance service of outsourcing companies and which takes into account main parameters of functioning and degree of influence of the servicing production upon main business processes. The developed methodical approach could be used as a tool of expansion of sales markets of the service sphere enterprises by means of assessment of needs of customers and establishment of the target-oriented market segment.