CF Dictionary · Theory of Constraints Terms

Buffer (ToC)

Extra capacity or inventory placed in front of a step (especially a bottleneck) to absorb variance.

A buffer in ToC is extra capacity or inventory placed in front of a step — usually the bottleneck — to absorb variance and keep the bottleneck fed.

Why buffers

  • The bottleneck can't run out of work. A starved bottleneck wastes expensive capacity.
  • Variance is real. Downstream steps fluctuate.
  • Margins protect against surprise. A buffer is margin by design.

Buffer vs. inventory

  • Inventory. Idle stuff sitting around.
  • Buffer. Deliberately-placed idle stuff protecting the bottleneck.

ToC distinguishes: a buffer is strategic; inventory is often accidental.

Where to place buffers

  • In front of the bottleneck. Most important.
  • In front of critical steps. Anything with high cost of starvation.
  • Not in front of excess-capacity steps. They don't need protection.

CF's adoption

CF treats buffers as a general design principle:

  • Time buffers. Margin around deadlines.
  • Skill buffers. Skills beyond current need.
  • Resource buffers. Money, energy, attention in reserve.
  • Practice as buffer. Automated skills don't fail when tired.

"Buffer: Having extra parts in front of a workstation to protect against variance." — LessWrong summary of CF