The concept of maintenance in the field of complex equipment was developed in the USA being quickly adopted by European countries and Japan. The American maintenance concept has the significance of creating a support system for industrial equipment functioning. Functional maintenance is one of the most frequent used methods in maintenance management for industrial enterprises. This paper tries to present some aspects related to the systemic approach of the functional maintenance model, starting from technical elements of the maintenance process but also taking into account the economical perspective i.e. maintenance-related expenditure.The final part of the paper presents a systemic method of representation of the model, taking into account the two mentioned aspects.