Flow

Drum-Buffer-RopeDBR

A Theory of Constraints scheduling method that paces the whole plant to the bottleneck and protects it with a time buffer.

Drum-Buffer-Rope (DBR) is the scheduling mechanism of the Theory of Constraints. The drum is the constraint, which sets the production beat; the buffer is inventory/time placed before the constraint so it never starves; the rope is the signal that releases raw material into the system only at the rate the drum consumes it.

DBR delivers much of the lead-time and WIP benefit of a pull system while focusing all control on the single resource that limits throughput.

Go Deeper
Theory of Constraints guide→
Related Terms
Theory of Constraints
A management philosophy that every system has one constraint limiting it, and improvement means managing that constraint.
Bottleneck
The process step with the lowest capacity, which sets the maximum throughput of the entire system.
Pull System
Production triggered by actual downstream consumption rather than forecasts — work is pulled by demand.
CONWIP
A pull system that caps the total work-in-process in a line, releasing new work only as finished work exits.
Throughput
The rate at which a system produces finished, sellable output — ultimately limited by the bottleneck.

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