Throughput

Throughput is the rate at which a process completes units of work over a period of time — orders shipped per hour, transactions processed per second, or claims closed per day. It describes output, not the speed of any single unit, which is what cycle time measures instead.

The two are linked through Little's law: throughput = work in process / cycle time. Maximum throughput for an entire process is capped by its slowest step, the bottleneck, no matter how fast the other steps run; speeding up a non-bottleneck step rarely changes total output. This is why throughput is usually measured and managed at the level of the whole process rather than any one station.

Practitioners use throughput to size staffing and equipment, to compare performance before and after a process change, and, in manufacturing, alongside metrics like overall equipment effectiveness to separate output loss from availability loss versus quality loss. A common pitfall is reporting average throughput while hiding its variability, or optimizing throughput at a station that isn't the bottleneck, which improves a local number without changing what the process actually delivers.