In answer to your question Veloo, SITA and LIDO are both companies which provide computerised flight planning system to airlines. If you want to generate a route i.e. let the system make a route for you (rather than fly on a fixed route that you have built and put into the system), then it will look at the airways and any restrictions, RADs, CDRs etc and build the best found for the time of the flight on that day. Flight plans also take into account the winds and the performance of the aircraft and so should give you the optimum route on the day.