Reply To: Cost index calculation
the big thing about cost index is that real trajectory optimization considers altitude simultaneously, and this can have a much bigger impact on flight time. On a short haul flight of 1:45, you can experience a difference of 10-12 minutes between maximum range cruise (CI=0) and minimum time (CI=999), of course at the cost of fuel. But this makes delay cost optimization extremely important, as those 10 minutes can make the difference between getting you passengers connected or not. Furthermore, in some cases, CI will give you a time advantage with very little extra fuel burn.
Together with dynamic inflight updates, CI can be very useful and efficient in delay cost management, even on short-haul flights.