Allow Location-Allocation to determine optimal locations for Existing Facilities?

[LarryGaudieri]

I am performing a series of analysis for our county's fire rescue. One question asked was it possible for me to allow Location-Allocation to determine the best locations (from existing facilities) to meet a data set of existing demand ( a year's worth of incident responses)?

I wasn't completely sure if it was possible or how the work flow would be. Again, taking existing fire stations, can Location-Allocation move those facilities to optimal locations to better meet the demand of the incidents?

Thanks to anyone who can help me out...

[LarryGaudieri]

Incredible. I've been looking for someone who can help me test and validate

the analysis by doing what you've described. With your shared knowledge, I

can gain a little confidence that I have control of the analysis design (a

scenario) and be able to explain it's result (the outcome).

I'll be in touch Jay as I get it ready....thanks again.

[JaySandhu]

You may also want to look up work that Mike Price does in this area of fire/emergency response. E.g.,

http://www.esri.com/library/ebooks/fire-mapping.pdf

Jay Sandhu

[LarryGaudieri]

Jay,

Thanks for the direction, it worked very well. However...LA responded to demand much more optimistically than Service Area did with impedance in both runs. So, in instances using SA, the service area envelopes validated the impedance but using LA, the impedance didn't have at least a similar effect. Has this been your experience as well?

[JaySandhu]

I did not understand what you mean by service area validated the impedance but LA did not have similar effect.

Service area grows uniformly outwards and the polygons are an approximation to cover all the roads traversed from the starting location.

Jay

[LarryGaudieri]

Sorry Jay, when I ran service area analysis using the same impedance that I

used for the LA analysis, the service areas seemed to replicate my response

data delays (the incident data shows response time) so the service areas

were impeded as well and more or less coincided with the data.

When I ran the LA analysis and used a time break of 7 (the same break I

used for service area) there were greater responses by LA than there seemed

to be in the polygon limits of the service areas. Everything I'm running is

based on my road network model with impedance, and delay times leaving

facilities. When one looks at the result of the service area and the gaps

of incidents (or demand) not responded to and then compares those same

areas in the LA result. The LA result seems a little more optimistic at

responding to demand against the impedance.

Does that make better sense?

[LarryGaudieri]

Hey Jay,

Thanks for all your help. I am now being asked to use LA to show 2 fire stations with increased capability (such as allocating additional rescue or transport vehicles from one facility to another). I have read about weighting and that it is used only in the market share solvers. Tried it once but ended up with over 100,000 line solutions...wasn't expecting that. Do you have any tips?

[JaySandhu]

I think the first question to ask/answer is what should additional resources at a fire station do? Does it increase its ability to reach further? Or does it ensure that more services are available to the same population so that you can tally who does and does NOT have this service available? Without a goal it is hard to say what/how to use Location-Allocation in this case.

Jay Sandhu

[ChrisDonohue__GISP]

To state what Jay Sandhu is saying in a different way, is there a specific set of goals you are trying to achieve?  For example, an advisory or regulatory limit on how fast apparatus can respond?  I mention this as our City's Fire Department has a set response goal time they want to meet, and since our City is growing, they are constantly re-evaluating their coverage so they can see if that goal can continue to be met.  Additionally, they need to plan out new Fire Stations so the new developments can also be covered while continuing to provide the same (or better) response times to existing areas.  So knowing the goals and the context that goes with them is critical to formulating a good analysis.

Chris Donohue, GISP

[LarryGaudieri]

Thank you both for your responses. The criteria have been set for my project as on-scene goal times for emergency medical response of 7 minutes. This is just one aspect as we are master planning both operational and future planning aspects.

Reactive changes in operations, and exploratory planning and analysis for future siting. This particular exercise is to see how moving 2 apparatus (one each from 2 stations) to another 2 stations closer to a kernel density spot of over-goal responses would affect the "hot spot". So, it would be making those 2 stations more capable in response than surrounding stations.

I tried weighting the stations and running LA but the line solutions were in the hundred-thousands. I wasn't sure I could explain what had happened or demonstrate anything substantive on the result.