What is a pallet pool?

A pallet pool is an automated storage and exchange system attached to one or more CNC machines (most commonly horizontal machining centers). Pallets with fixtured parts are queued in the pool and exchanged into the machine automatically, allowing the machine to run unattended for hours or days.

Why do pallet pools underperform their potential?

Three reasons: scheduling that ignores pallet identity, fixtures that are not built or staged in time for the next sequence, and operators who load whatever fits instead of what the schedule says runs next. A pallet-aware scheduler addresses all three.

Is pallet scheduling only for HMCs?

No. The same logic applies to any automation cell where the binding constraint is a fixturing or staging resource rather than the machine itself — robot-tended VMCs, FMS, automated grinding cells, and bar-fed lathes with sub-spindle automation.

Pallet Scheduling — Manufacturing Scheduling Glossary

Definition

Pallet scheduling — also called pallet-aware scheduling — is the practice of sequencing work on automation cells (HMC pallet pools, FMS, robot-tended cells) by reasoning about pallet identity, pallet position in the pool, and pallet–fixture–part assignments. Most schedulers schedule machines; pallet-aware schedulers schedule pallets, because in a pool the pallet, not the machine, is the binding constraint.

Why it matters

A pallet pool with twelve pallets can theoretically run lights-out for an entire weekend. In practice, most run at 30–50% of that potential because the scheduling system was designed for standalone machines. Pallet-aware scheduling routinely lifts unattended runtime by 40–80%, which is the entire justification for the automation investment.

Common failure mode

A planner schedules jobs to "the HMC" the same way they schedule a standalone mill. The cell runs out of fixture combinations at 11 p.m., chokes, and sits idle until first shift arrives at 6 a.m. Seven hours of unattended capacity lost on a single night, repeated every night the schedule is built without pallet awareness.

How Skody approaches it

Skody models each pallet, each fixture, and each part-to-fixture mapping. The scheduler sequences pallet swaps to maximize unattended runtime, identifies the next fixture build required to unlock more lights-out hours, and tells operators which pallets to load before they leave for the night.

Lights-Out Machining

Running CNC machines unattended outside of staffed shift hours.

Finite Capacity Scheduling

Scheduling that respects the real, limited capacity of each machine, operator, and tool.

Constrained Resource

Any finite resource that limits how much work the factory can complete in a period.

Setup Sequencing

Ordering jobs on a machine to minimize total changeover time across a batch.

Work Center

A grouping of one or more machines or stations that share routing and capacity.