Maintenance free operating period - an alternative measure to MTBF and failure rate for specifying reliability?

The paper analyses the concept of maintenance free operating period (MFOP), the reliability requirement driven by the Ministry of Defence (UK) for the next generation of future aircraft to be included in the fleet. Since the traditional reliability requirement MTBF (mean operating time between failu re) has several drawbacks, the immediate reaction would be to analyse the c redibility of the new measure MFOP against MTBF. The paper discusses variou s issues associated with MFOP. Two mathematical models are developed to pre dict the maintenance free operating period survivability (MFOPS), one using mission reliability approach and the other using alternating renewal theor y. The paper also analyses cost implications of MFOP to the customer and to the producer. (C) 1999 Elsevier Science Ltd. All rights reserved.