Throughput
Definition
Throughput is the rate at which a system produces sellable output, such as units per hour or orders shipped per day. In theory-of-constraints usage, it means the rate at which the business generates money through sales.
In Practice
Throughput measures flow, not effort. A factory that produces 500 units a day into a warehouse where they sit unsold has activity; throughput in the constraints sense only counts when product ships and revenue is earned. This framing keeps improvement work focused on the end-to-end system rather than local efficiencies.
Throughput connects tightly to two companions via Little's Law: inventory equals throughput multiplied by flow time. Hold throughput constant and cut flow time, and work-in-process falls proportionally. This is why lean initiatives that shorten cycle times automatically reduce inventory, and why a warehouse can raise daily shipping capacity either by adding labor or by removing steps that make each order take longer.
For planners, throughput is the sanity check on plans: a schedule that loads the plant beyond demonstrated throughput at the bottleneck is fiction, no matter what the planning system says. Tracking demonstrated versus theoretical throughput reveals hidden losses from changeovers, breakdowns, and quality issues.
Related Calculators
Related Terms
A bottleneck is the resource or process step with the least capacity in a system, which limits the output of the whole chain. Total throughput can never exceed the bottleneck's rate.
Lean ManufacturingLean manufacturing is a management philosophy focused on maximizing customer value while systematically eliminating waste, such as excess inventory, waiting, overproduction, and defects.
Capacity PlanningCapacity planning is the process of determining the production, storage, and labor resources needed to meet expected demand, and deciding how to close gaps between required and available capacity.