BOOKS OF RtfiDIfGS - PAHO/WHO

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REVELLE possible within ilhe location concepts discussed tliur, lar. whici focus
ET Al.. on tile dispatchl location of emergency vehicles. Achievement of a
standard lor tile demandl-point.to-hospital Ieg of the transportation
triangle (depot lo demand to hospital to depot) can ciily be influenced
by the locations of emerg;ency care hospitals.
The locations of aiuch hospitais in turn affect the vehicle loca.
tions needed to achieve standards on the entire depot.to-point.ol-care
time. The twin problems are interlocking and complex, but potentially
solvable. Together the two problems of ambulance location
and location of emergency care facilities comprise almost all of tihe
transport segment of emergency care. Seen as two interlocking problenms.
they give rise io a more basic question:
With limited resources lor purchase and opcration of vehicles and for
establishment and opcratio.m of emergency care facilities. dctennine the
nunmber and localionís of boill ¡Ihat will maximize the proportion of resloScs
occurring withi.i the lime sandard.
A complementarity of achievement exists between emergency vehirles
and emergcncy care facilities. An additional emcrgency care
facility miglht oblvi;:te the need for I ,r (to choose a number) emergenty
vehi(lies by dliiiiisling thc total time from dispatch to final
care site. The maximal covering model will permit these trade-offs
to be examined. The relative costs of mobile and fixed facilities
would indicate whiclyhuoicses were appropriate and open the possi.
bility nl cost.eflcctilness comparisons that could Icad to EMS syst(..
,. wuld be'1.both functionally and economically optimal.
Summary and Conclusions
We have discused the remarkable hainiony between the structure
of the maximal covering model and ihe goals of policy nmakera.
The ability of the model to deal with multiple objectives and to opti.
mally asaign special equipment to optimally-located depoits, as in our
fire department study, indicates the model' general utility in a wide
range of location problema. It should be particularly useful in plan.
ning and evaluating emergency nicdical systems.
In location research (perhaps in other types of resc'rchl as well) a
aymbiosis exists between the setting of a particular application asid
the development of models. Lcation models aid in conceptualizing
a problem in a particular setting and the special characteristica of
the setting feed back to enrich the location model. We expect such
aymbiosis from the EMS setting. We believe that location analysis
can make a significant contribution to the evaluative structure oí
such services and that tlis setting will add new and important di.
mensions to location ¡clcarch.
l1tALTH.' REFERENCES
silavíC I. Lea. A. An annouted bibliogiaphy olf , lei io.aUocaIoU I Wolking pH'ry. I>.
lESAtmti of GCeogaphy, Uniacnisiy olf uunto. 1973.
ReVelke. C. D. Marks, and J.C. l.iáeman. An analysti ol privale and publitc wc
lor loation modrit. Mondge Sti 16:62 July 197'0.