Bottleneck

A bottleneck can be a machine, a work center, a team, a dock door or a single process step such as quality release. It differs from a temporary constraint caused by a breakdown or an absence: a bottleneck stays where it is as long as demand and product mix do not change. Work‑in‑process accumulates upstream of it, and the resources downstream wait for material.

Take three stations in series with effective capacities of 120, 90 and 110 units per hour:

• Line output is 90 units per hour, set by the second station.
• Raising the first station to 150 units per hour adds no output; it only grows the queue in front of the second.
• One hour of stoppage at the second station costs 90 units that can only be recovered with overtime. The same hour at the first station costs nothing if at least 90 units wait in front of the second, and its 30 units of spare hourly capacity rebuild that buffer in three hours.

Bottleneck in practice

Utilization reports are a weak guide to where the bottleneck is. A station starved of material shows low utilization even if it is the constraint, and a station running at 95% may simply be working ahead of what the next step can take. The physical signs are more reliable: where work‑in‑process queues up, which resource the downstream steps wait for, and which step the shift leaders protect from breaks and changeovers.

The bottleneck also moves. With a mix weighted toward products that need long processing at one station, that station limits output; when the mix shifts, the limit moves elsewhere, so a capacity plan built on one mix can point to the wrong investment. In a warehouse the same happens within a day: over a full shift picking may have spare capacity, while packing stations or the sorter become the constraint in the hour before truck departures. Faster picking then only moves orders sooner into the queue in front of packing.

Logio locates bottlenecks and tests where added capacity actually raises output through dynamic simulation before an investment is approved, and resolves them in intralogistics and material flow and production capacity planning projects. On the inbound side, DC replenishment in Veritico STOCK includes capacity planning for warehouse, transport and labor and balances supplier orders into a daily min–max range, which smooths peaks at the receiving dock.

Related terms

• Capacity Planning
• Production Scheduling
• Warehouse Automation
• Master Production Schedule (MPS)