MTBF in parallel RBD

[Anonymous]

[Originally Posted: 11/7/00--Transferred by ReliaSoft Moderator]

LS I am looking for a formula that gives MTBF as a function of individual MTBF in a parallel RBD, where n out-of-m needs to be functional?

[Dr. Dave Olwell]

[Originally Posted: 11/13/00--Transferred by ReliaSoft Moderator]

NO such luck. If you assume a common distribution for the items, you can get a general expression for the reliablity of the k of n system using binomial identities, but it does not easily simplify or transform into any statement about the system MTTF. You'd have to integrate the reliablity to get the MTTF, and while that can be done, it is not a simple formula in terms of components means.

Sorry.

If you'd like help with your particular application, let me know by private email.

Dr. Dave