I don't think so. Or what's the unit in this case? If you think of it as "the probability that a problem with at least some given severity occurs", then you can

I don't think so. Or what's the unit in this case? If you think of it as "the probability that a problem with at least some given severity occurs", then you can model it as the combined independent probability of N dependencies and you end up with the classic 1 - (1 - p) ^ N, so asymptotic behavior for large N.