If you are supposed to compute the aggregate RDF, does that mean compute the RDF for all the components and then add them up to get the aggregate RDF? I have searched my course book and the internet to see how you compute the aggregate RDF, with no luck. The problem says to assume a series combination of elements for your calculation. So I thought you would multiply each reliability in the series and then subtract that number from 1 to get the RDF. Then i read that "aggregate" means the "sum of," so I thought I would compute the RDF for all the elements, add them together and then subtract that number from 1 to get the aggregate RDF.

Below is the problem:

Using the information from Table 1, what is the aggregate RDF for a vehicle configuration using 3 fuel pods? Assume a 'series' combination of the launch elements shown for your calculation. The reliability of the 4 elements are: .991, .995, .993, and .997 for each fuel pod. Since the problem says it uses 3 fuel pods, you would have to compute the .997 for the fuel pod three times for a total of 6 elements in the problem. Am I on the right track? The RDF formula is: RDF=1-reliability. I got 0.03 as the RDF. Is that correct? Please let me know what you think.

Thanks,