Some features that would be nice to add to the game:
* A counter on each section of the chain to show how much of its current capacity is used.
* On the graphs for the reports, additional lines showing the resupply thresholds for each part of the chain, as well as additional bars showing the various random events.
Also, 20 rounds seems really long. Maybe track statistics mid-round (for better resolution on the statistics) and make the game last only 5 rounds, say?