To make the situation even more complicated, we now assume that instead of having a possible fixed length delay of 10 days, this number is subject to uncertainty. This can be done easily by creating another node which we name “Delay”. We then create a reference to this node by using the “Create reference…” command in the model menu. In this case we just let the reference name be the same as the node name, i.e., “Delay”. 

The point is that we need to choose a name for the reference which is unique among the references. Hence, if we had created another reference earlier with the name “Delay” as well, then we would need to come up with something else this time.