Wave picking: when waves pay off, and when they do not

Short answer: a wave groups orders that are picked together. It pays off when several orders share the same zones and locations, so a picker covers more work in one walk, and when dispatch runs in rounds. When an order is large or urgent, one order per picker is simpler and safer. In NG WMS a wave is built in five steps and stays a draft until someone deliberately releases it.

What a wave is, and what it is not

A wave is not just today’s list of orders. It is a decision to reserve, replenish and release a set of orders to pickers as one unit. That is why it is built from pre-picking, where orders are filtered by day, delivery round, shortages and postponed deliveries, and where priority or round can be changed in bulk.

A good wave cuts repeat visits to the same locations. A poor one just moves the waiting elsewhere — to a sorting step nobody planned for, for example.

Discrete or Cluster

Cluster is the default in NG WMS, because with many small orders the walking is the most expensive part of the job. With either strategy, several pickers can be put on the same wave, and the wave can be split into sub-tasks per zone, so each person works their own part of the warehouse.

When the same items repeat across many small orders, Cluster gives the biggest saving: the picker visits a location once, and the goods go straight into the right order, with no separate sorting step after picking.

Five steps before the picker sets off

1. Selection review — which orders go into the wave.
2. Configuration — strategy, whether several pickers work on it, group name and a note.
3. Reservation — in full or with a shortage.
4. Replenishments and exceptions — what still needs refilling and what stands in the way of release.
5. Release or draft — the wave is released now or waits.

The fourth step is where mistakes are caught cheaply. Blockers, which stop release, are shown apart from warnings, which only need attention. An important blocker therefore does not get lost among ten minor notes.

Orders with a shortage

Waiting until every item is in stock often means nothing moves at all. So an order with a shortage may join a wave: what exists is reserved, the order is flagged as partially reserved, and the shortage is tracked in a separate report. Whether to ship part or wait stays a human decision, but one based on accurate data.

When a wave makes no sense

• When there are few orders and they differ, grouping saves no walking.
• When one order is urgent, releasing it on its own is faster than waiting for a wave to fill.
• When replenishment is late, a wave only passes the waiting on to pickers — which is why the replenishments and exceptions step comes before release, not after.

A released wave is not final: it can be closed, returned to draft or cancelled, and an order can go back to pre-picking. How waves, checking and packing work together is described on the Outbound page, and the replenishment that should arrive before the picker on the Stock and replenishment page.