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Routing tool with Tolerance & Manual Changes

March 22, 2011     ShareThis

The nature of heuristic algorithms is such that they may look optimal for one set of data and suboptimal for another. The meaning of this in the route planners world is that when you use a routing tool and get your route plan, you cannot always be sure that it is the best and there is a chance (even if a small one) that there is a better route plan hidden somewhere under the data. In addition, a route plan may look optimal to one user and less optimal to another. The minimum distance or minimum time are not always the only parameters that affect the optimality of the solution.

The way to overcome this difficulty is to check and compare different scenarios and select the one that best suits each one’s objectives. The practical way of doing so is by selecting different parameters (where available) that affect the algorithms and check the results.
Everyone using a GPS device is doing this, even unconsciously, when he changes the route plan objective from Minimum Distance to Minimum Time and then decides which one to follow. Our routing tool offers even a third objective which is a combination of Minimum Distance & Minimum Time.

Let’s take an example which relates to the No. of addresses per route.
Suppose you have a data set of 50 addresses that you want to divide between 5 routes (10 addresses per route). In this example the addresses are distributed in an uneven way geographically having 15 addresses in one place, 5 in another and so on.

Dividing these 50 addresses evenly between 5 routes, even if you get a minimum distance plan, may not be the optimal solution because you might have to send two drivers to the same geographical position (the one with 15 addresses). But if you would allow a deviation (tolerance) of 20%-30% in the number of addresses per route, you may end up with a much better – more optimal – route plan.

Since we show the entire route (in this case routes) on the map, this scenario will be visible to the user and if he doesn’t want to send two drivers to the same location, he can therefore decide to avoid it by changing the deviation parameter or by using the Manual Changes as described below.

The same may hold for the Manual Changes utility embedded in MyRouteOnline’s algorithm.
The user may want to manually change an address location within the same route or move an address from one route to the other. This change may have an effect on the rest of the addresses or not, according to the user’s decision.

If you need an address to be visited earlier or later without changing the order of the other addresses, you can uncheck the box offering to optimize the remaining addresses. As much as we recommend using this option, we realize that in some cases, there are other constraints such as Time Windows that affect this change and that’s the reason we allow the user to choose what suits him best.