When to Use Pick Waves: Timing Strategies for Warehouse Efficiency

Knowing when to run pick waves is as important as knowing how to run them. Timing affects labor utilization, packing throughput, carrier pick-ups, and customer service levels. This entry guides beginners through triggers, scheduling strategies, and practical tips for choosing the right wave cadence.

Common triggers for launching a pick wave

• Carrier pickup cutoffs: The most common reason to run a wave is to meet carrier deadlines. Orders that must ship before the carrier arrives are grouped and released with sufficient lead time for picking, packing, and staging.
• Order promise times: Customer-facing promises like same-day or next-day delivery create natural waves that must be run to meet SLA commitments.
• Peak demand periods: During events like Black Friday or seasonal surges, waves are scheduled more frequently to process increased volumes and avoid bottlenecks.
• Resource availability: Availability of pack stations, forklifts, and staff can define wave timing so work volumes align with capacity.

Deciding wave frequency

Wave frequency ranges from continuous waves every few minutes (micro-waves) to a few large waves per day. Choose frequency based on:

• Order arrival pattern: High, consistent order flow favors frequent waves to keep a steady pace. Sporadic batches of orders favor less frequent waves.
• Packing capacity: If pack stations are a bottleneck, smaller, more frequent waves help even out the flow rather than dumping too many packages at once.
• Warehouse layout and travel times: Long picker travel times can justify larger waves with batch picking to maximize efficiency.

Examples of wave schedules

• Hourly waves: Common in mid-sized e-commerce facilities where orders arrive steadily and carrier pickups are multiple times a day.
• Twice-daily waves: Typical for retail DCs aligned with morning and evening truck departures.
• Event-driven waves: Ad hoc waves opened when a critical mass of high-priority orders accumulates (e.g., large promotional campaign spikes).

Timing considerations for special needs

• Temperature-sensitive goods: Run small, frequent waves to reduce the time perishable items spend outside controlled environments.
• Hazardous materials or controlled goods: Coordinate waves with compliance checks and specialized handling resources to avoid delays.
• Marketplace cutoffs: If selling through marketplaces like Amazon or other platforms with strict cutoffs, schedule waves to close before those deadlines.

Aligning waves with labor planning

Waves should reflect the workforce schedule. During peak days, increase wave frequency and add temporary staff or overtime. On slower days, fewer waves with flexible assignments reduce idle time. Cross-training staff to shift between picking and packing during waves improves adaptability.

Wave sizing and staging time

When scheduling a wave, account for upstream and downstream time: the time to pick, to pack, and to stage for carrier pickup. A wave that leaves no buffer for exceptions will frequently miss cutoffs. A typical planning approach is:

1. Estimate average pick time per order and packing time per package.
2. Multiply by the number of orders you plan to include.
3. Add contingency time for exceptions and staging (often 10–20%).

Monitoring and adapting wave timing

Start with conservative timing and measure outcomes. Key metrics include wave completion rate, on-time shipments, average pick/pack time, and exception rates. Use these metrics to tighten wave windows and increase throughput gradually.

When not to use waves

If orders are highly unpredictable and require immediate fulfillment, continuous flow or single-order picking may be better. Similarly, very low-volume operations may find wave planning overhead unnecessary.

Practical tips for beginners

• Run a time-and-motion study to estimate realistic pick and pack times before defining wave windows.
• Coordinate wave timing with carrier schedules and communicate pick/pack closing times to customer service so promises are realistic.
• Start with a pilot: run waves in one area of the warehouse or during a limited time window to test assumptions and collect data.

In short, pick waves should be scheduled when they help align labor, capacity, and carrier requirements. By starting conservatively, collecting data, and adjusting frequency and size, operations can tune waves to maximize throughput without risking missed shipments or overloading downstream processes.