Thank you for your reply.
So there is no converstion factor between environments for NPRD.
To calculate the reliability ESTIMATE in the automotive field. I need the failure rate of “pipe, exhaust” p2-631 in NPRD2011. This failure rate does not exist (for this evironnement).
What is the best way for me to evaluate the rate of failure of the “pipe, exhaust”?
1- feedback experience (field data) (only for parts already operating)
2- method strength / stress (it only takes into account the maximun effort without considered the environment, rain, sand, salt spray, …)
3- RDGT (if you have well-defined test conditions.)
Field data for similar components that are used in an environment that is sufficiently representative of the conditions for your proposed design would provide the best estimate of an expected failure rate. A second option would be to use test data if the test environment can be constructed to approximate the fielded environment. As a final resort, the merged failure rate values across all environments in NPRD could be considered. In the example that you provide, this would be the first entry under “Pipe, Exhaust” without an environmental indication. The data merge methodology and how merged failure rates can be identified in NPRD are described in Section 1 of the publication.