Orders are sorted for each 10 km square.
The 10km square furthest from the depot is identified.
The remotest 10km square is further divided into 1km squares and the orders re-sorted for each of these.
The scheduler begins to build up a load for the furthest 1km square.
As the orders are re-sorted, the total time required is calculated by adding together the driving time and the loading/unloading times for each delivery point and the driving time to the next delivery point.
The scheduler moves on to build up the load for the next most remote 10km square and so on.