# Ranking multiple break values in Service Areas

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07-25-2013 06:10 AM
New Contributor
I have multiple points on my map that I need to create service areas for. Each point has their own calculated break value. E.g. one point has a attribute-created break of 10 while another has a value of 6.

I need to run an analysis so that a service area is created around each point without overlapping polygons. However, when I calculate around a dense region of points, the points with a lower value seem to overtake and don't allow for those points with a high value to create a proper boundary.

I've included an image here. The polygon in red has the highest value of 7000, while the surrounding gray polygons have values of 3000. How do I give the points with higher break values priority to be the largest? [ATTACH=CONFIG]26195[/ATTACH]
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2 Replies
Esri Regular Contributor
Please ask this question: When you have two facilities nearby and their service area overlap and you choose non-overlapping, what should happen to the overlap area? Should one facility get edges that are closer to another or should they be split such that each facility gets those edges that are closest to it?

Service areas are "grown" outward to the specified distance. When you specify non-overlapping, then the overlap areas can only be assigned to one of the facilities. By definition, edges are assigned to their closest facility. When an edge is equidistant to two facilities then the resulting service area will split the line at the place where it is equidistant to the two facilities.

So back to your case, if you have a facility with 7000 meter break surrounded by a number of facilities with 3000 meter break, the 7000 meter break facility is not going to get more edges assigned to it IF those edges happen to be closer to other facilities. So in your attached picture, other facilities "crowd out" your facility with larger break value as that is the solution to the non-overlapping case.

If you want to "preserve" a 7000 meter around a facility then I suggest you solve that facility separately, then use the resulting polygon as a barrier polygon in another service area layer loaded with other facilities and solve. Combine the results.

Jay Sandhu
New Contributor
Thank you for clarifying this for me. I was originally trying to think of ways to run two levels of service areas and I thought of using the polygons as barriers but I wasn't sure if that was the correct method. I'll give this suggestion a try. Thanks Jay!