Thank you Johan. The "devil is (indeed) in the details". It seemed like a reasonable approach but before I wandered too far off the reservation I thought I would consult the experts.

A sanity check: Is it reasonable to use this approach to model the reliability of larger systems? For example a system consisting of a modular, multi-voltage power supply, an instrument chassis with a backplane, and up to 18 parallel modules used for a variety of data collection or instrumentation tasks. Specifically I'm referring to modeling a National Instruments PXI chassis with backplane connected instruments or DAQ devices. Generally there is reliability data for each subassembly including the chassis. So I'm curious to know if these new reliability tools could be reasonably used to assess the anticipated system reliability rather than just using them for simple circuits?

I'm not really asking how to do it as much as I am asking is it a reasonable use of these tools. I recognize there are a lot of other reliability prediction tools out there.