It can be a tricky algorithm because you might need a deep queue in normal operation to smooth out momentary bursts of traffic.

FORBES: What Have Been Facebook's Greatest Technical Accomplishments?

In health, we will set out tomorrow a new guarantee of treatment within a set time which starts from the moment a patient is referred by their GP - not the time that they get onto the queue for their operation.

BBC: NEWS | UK | Politics | Full text: Blair on public services