This paper is devoted to obtain the reliability equivalence factors of n independent and non-identical components series system. The lifetime of each component is assumed to be exponentially distributed random variable. The results introduced by Rade [Rade L. Reliability equivalence. Microelectronics and Reliability 1993a;33:323-5; Rade L, Reliability survival equivalence. Microelectronics and Reliability 1993b;33:881-94.] can be obtained as special cases from this work when n = 1.2 and assuming the components are identical. (C) 2000 Elsevier Science Ltd. All rights reserved.