There are up to 15 desks working 24‑7 at Toronto’s flight dispatch centre. Sophisticated software called LIDO (Lufthansa Integrated Dispatch Operation) juggles a multitude of factors to come up with the most feasible route. Many routes change on a daily or even hourly basis. Upper winds are near the top of the list of parameters that affect route planning. Among other factors that go into the number crunching are distance, airspace restrictions, inclement weather, altitudes and aircraft weight. Occasionally, pilots can query the routing and it can be modified if need be.