8Cini P F, Griffith P. Designing for MFOP: towards the autonomous aircraft. Journal of Quality in Maintenance Engineering, 1999, 5(4): 296-306,.
9Chew S P, Dunnett S J, Andrews J D. Phased mission modelling of systems with maintenance-free operating peri- ods using simulated Petri nets. Reliability Engineering and System Safety, 2008, 93(5): 980-994.
10Kabashkin I. Discrete event model of maintenance free operating time for aerospace based telematics systems. The 9th International Conference MMA2004. 2004: 29- 31.