Dynamic Durations in Production Scheduling

Hi

We are in the middle of a PS implementation and have encountered some challenges with modeling our manufacturing mill. We have modeled our bottleneck resources with no problem, but we have several stages in our process where the item is stored for a dynamic timeframe. One example would be all items use machine A, which moves to either bin Y or Z, both of which feed (not simultaneously) into machine B. We need to model bins Y and Z for proper sequencing and changeovers.

Has anyone encountered a similar issue modeling their plant? If so, what have you done to work around this constraint?