FD347 said:
The CADS relocations are rarely used now. The CADS' selection process involves going through the alarm assignment and choosing the nearest unit that will not cause another open area. Usually that means using a unit that would be assigned on the next alarm level.
What the relocation program does do well is tell you which houses to fill so as to close all of the open areas with the least amount of moves.
Frank is completely right here. There are two phases to the relocation process: (A) what house/s should be covered, and (B) what unit/s will we use to cover them or "relocate". The CAD relocation program is a quick way to identify which units you MAY want to cover, but as for the choice of what company is to be used to relocate, the choices almost always SUCKED.
It will probably be impossible to design a system that calculates part (B) considering all the variables a dispatcher must take into account at the time
FDNY operated on an RN (Response Neighborhood) idea. If two similar units (Engines or Trucks) are assigned first and second due to a fixed number of boxes, and are both "seriously unavailable", that is expected to be unavailable for a set time period, a suggestion would be made to fill one of the units.
A better system was proposed some decades back: If ANY single unit was "seriously unavailable" and the adjoining second due unit was greater than x minutes from the uncovered district, a relocation was suggested. A prime example might be if Engine 70 on outlying City Island would be OOS, a relocation to E70 would be suggested. Of course that is what the dispatcher does now, but could also apply to other companies in outlying areas or those with very large response areas such as in eastern Queens or Staten Island. If a unit and its RN partner were relatively close, a relocation may not be needed or suggested.
Back to the static pre-planned relocations printed on the back up assignment cards. These, like many FDNY concepts, operated on the assumption that there was only one fire going on at the time. A usually always incorrect or dangerous assumption. And that is why pre-planned relocations were not worth the paper they were printed on.