When you want to make changes to a Route, you can use the Drag and Drop function (read more about it here) or you can play with Time Windows.
As far as this latter method is concerned, let's look at an example.
You have two groups of Orders, one located North of your Driver's initial position and one located South of it.
In order to receive an optimal Route Plan, you click on Plan Optimal Routes, but let's say that the Viamente Route Planner suggests a Route which is different from your expectations: it goes South (and serves the South group of stops starting at 9am) and then it goes North (and serves the North group starting at 10am).
If you feel for any reason that going North first and South then is better, you should try to modify the Route manually and see if the impact on the Plan is acceptable.
One quick way is to click on the first stop of the North group (it is Stop n.8 in our example, see above). A bubble appears and you can click on the link Edit.
Now you can edit the Time Window of Stop n.8 like this: leave the field Time Window Start untouched and modify the field Time Window End setting it earlier, to 9.30am.
Click Plan Optimal Routes again. This time the program will have to suggest a Route that must arrive at Stop n.8 earlier than 9.30am.
This way you will force the Route to go North before going South (notice in the screenshot below that in fact the numbers of the stops have changed: what was Stop n.8 has now become Stop n.1, and so forth).