Hi, I'm loving Kerbalism but have a question about the 'incentivize redundancy' option. From what I read, the idea is that building redundancy into a system should be better than simply choosing the "high quality" part option for increased reliability. I got curious as the the specific numbers and in the code it seems that it works the following way: when one component fails in a redundancy group, the other components in that same group have the time until their next failure doubled. I gathered that from the following bit of code:
if (m.redundancy == redundancy)
{
m.next += m.next - m.last;
}
and also the similar bit for unloaded vessels.
So I actually modeled out this formula to try to get accurate reliability estimates for parts. However, I noticed that even with the incentivization bonus, redundancy isn't often the best option as far as I can tell. Here's some plots I made for an antenna component:
As you can see, the high quality part is barely worse than double normal components for the short term, and better after about the MTBF is reached. Considering the weight savings of using the high quality parts (seems to only add 10% in this case), it seems that I would always chose high quality. If I needed really good reliability I'm guessing 2 high quality components beats 3x and 4x redundancy, but I didn't actually model that. Also, I should note I assumed single part failure times are calculated assuming a constant failure rate, so thus an exponentially decaying survival function i.e.: S(t) = e^(-t/MTBF).
Is this how the option was intended? Also, perhaps have I missed something or misinterpreted the code? I really like the idea of needing redundancy, but right now it just doesn't seem worth it.