A system and method for improving a causal network is provided. A new apriori probability is determined for a repair or a configuration factor within the causal network and compared to an old apriori probability. If the new apriori probability differs from the old apriori probability by more than a predetermined amount, the causal network is updated. Further, in another aspect, a causal network result is stored for a causal network, wherein the causal network includes a plurality of root causes with a symptom being associated with each of said root causes. An existing link probability is related to the symptom and root cause. An expert result or an actual data result related to each of the symptoms is stored. A new link probability is computed based on the stored causal network result, and expert result or the actual data result.