The present invention discloses a method and a computer program for optimizing the implementation of a maintenance program for maintenance units. In the method of the invention, an estimated duration is determined for each maintenance module, a periodic working capacity is determined for each serviceman carrying out maintenance programs and location data is determined for each maintenance unit. Further the invention comprises optimizing the maintenance work comprised in the maintenance modules for each serviceman in such manner that the unbalance between the working capacity of the serviceman and the amount of maintenance work required by the maintenance units belonging to the maintenance domain attended to by the serviceman is minimized and the required traveling from a maintenance unit to another is minimized, so that the number of maintenance modules located in the vicinity of each maintenance module is maximized.