Comment by clemsen

I would love to get more details on the linear-integer solve methodology, as it sounds impressive. Was the problem formulated to also work as a linear problem where the binary or integer variables were first treated as positive non-integer variables, and then checked using branch-and-cut (That's how I would do it)? Or did you do something differently?

  Fortunately, we found a different plan of attack: one
  which allowed the integer-linear-programming solver to
  explore the problem space more efficiently and find 
  optimal solutions faster. What previously took an hour, 
  now took 0.2 seconds.