I'm not sure I get the problem. Doesn't this just call for modeling a network of branches, nodes, with set of realistic max/min/stddev timings to traverse each

I'm not sure I get the problem. Doesn't this just call for modeling a network of branches, nodes, with set of realistic max/min/stddev timings to traverse each, and an inventory + desired times of trains to be released into the system? Is it that railroads don't have the expertise to do this? Hard to imagine. Why are railroad execs huddled around a physical table + map trying to propose timings for trains to run through? Maybe the article is simplifying things that makes it sound really inefficient.