The paper will provide a lifecycle cost-benefit analysis of the use of Prognostics and Health Management (PHM) systems and a conditioned-based maintenance (CBM) concept in future aircraft. The proposed methodology is based on a discrete-event simulation for aircraft operation and maintenance and uses an optimization algorithm for the planning and scheduling of CBM tasks. In the study, a 150-seat short-range aircraft equipped with PHM and subject to a CBM program will be analyzed. The PHM-aircraft will be compared with an Airbus A320-type of aircraft with maintenance expenditures equivalent to a conventional block check maintenance program. The analysis results will support the derivation of technical and economic requirements for prognostic systems and CBM planning concepts.