WIP and Little's Law

Little's Law

The law ties throughput, flow time, and WIP together.

highlighted = computed this step

Read the Law

The equation links the three exact quantities.

WIP=throughput×flow time\text{WIP} = \text{throughput}\times\text{flow time}
WIP and flow timeThe chart shows WIP from throughput times flow time.Little's Law WIP and flow timethroughput 12 jobs/hour; flow time 3 hours; WIP 36 jobscasethroughputflow timeWIPchangebase12336baselinewhat-if12224reduction 12basebase WIP 3612 x 3what-ifwhat-if WIP 2412 x 2what-if WIP 24; reduction 12deterministic Little's Law arithmetic only

Base Case

With this throughput and flow time, WIP is 36.

12×3=3612\times3 = 36
WIP and flow timeThe chart shows WIP from throughput times flow time.Little's Law WIP and flow timethroughput 12 jobs/hour; flow time 3 hours; WIP 36 jobscasethroughputflow timeWIPchangebase12336baselinewhat-if12224reduction 12basebase WIP 3612 x 3what-ifwhat-if WIP 2412 x 2what-if WIP 24; reduction 12deterministic Little's Law arithmetic only