"As an example: you point out that sometimes you get another call while ambulance A is moving to the former position of C, but do not weight that against the pr

"As an example: you point out that sometimes you get another call while ambulance A is moving to the former position of C, but do not weight that against the probability that no call will come subsequent to the previous call in the vicinity of C." Yes - that is correct - but for the example given the whole idea was to keep it simple. Things such as "fluid deployment" (which is moving A to C's old location) is a process that we already do. There is an attempt to redistribute ambulance resources for optimal coverage. But in reality, we find that, especially due to things like traffic, is the A will never get to C's location in time, and thus we dont actually have an optimal coverage of location in peak times. Also - there are so many reasons why we cannot always relocate A anyway. For example, perhaps A+B have just finished offloading patients at a hospital, or they are at their station/depot having lunch. "maybe the A/B--C situation comes up rarely enough that the probability of a call coming in that makes C a bad choice is so low that you really should always just choose C." This might be true - certainly the frequency of the calls will be a factor. We have one of the largest frequency of calls in the world, with an average around 1.5 incidents every minute 24/7 (but weighted with more of those occurring in peak times such as mid-afternoon and less at 3am in the morning).