Little's Law
The steady-state relation L = λW connecting average work in a system, throughput/arrival rate and average time spent in that system.
The Relationship
Little's Law states:
L = λWwhere L is the average number of items in the system, λ is the long-run arrival/throughput rate under stable conditions and W is average time in the system.
The relation is useful because it connects queue depth to latency without assuming a specific service-time distribution.
Boundary
The variables must describe the same system boundary and a stable observation period. Applying an arrival rate from one boundary to a latency measured at another produces a meaningless result.
In ASR, queued audio duration and completed workload can make the relation more useful than job count alone.