The weakest link in the system can usually be identified by observing queue behaviour over a number of rounds. You would expect to see a build-up of people before the weakest link and, perhaps a dearth of people directly after it, as illustrated in the image below.
![](assets/img/Game4Fig1.png)
When making the observations it is important to remember that different stations have different average capacities. This means that it is not necessarily the absolute number of people before a station that is important as that particular station may have the capacity to service the number waiting. Rather, the observation should note whether there is a tendency for the number to increase, i.e. does it have the capacity to cope with what it is receiving from previous stations?