We occasionally use a package called Lindo depending on what the problem is (typically unique transport optimisation problems), but try to formulate problems/so

We occasionally use a package called Lindo depending on what the problem is (typically unique transport optimisation problems), but try to formulate problems/solutions so they don't require a MILP solver wherever possible (it's better to remove any black boxes if you can). One advantage of Lindo is that it has a version that lets us integrate the solver into an excel spreadsheet, which helps us share the model with clients and makes it easier to explain to them (and let's them see the workings, as it's built in a tool that the client already knows how to use).