Lines Picked Per Hour

When picking feels fast but shipping still feels late

Lines picked per hour is one of the first warehouse productivity metrics people reach for. It is simple, it is familiar, and it feels objective. If you pick more lines per hour, you must be doing better, right. Sometimes. Other times, lines picked per hour becomes a scoreboard that rewards the wrong behavior and hides the real bottleneck.

The problem is that customers do not buy lines. They buy orders. Retailers do not audit lines. They audit compliance and delivery. If picking productivity rises but packing is overloaded, or replenishment is late, or carrier pickups are tight, then the day can still end with late orders. Lines picked per hour is a useful metric, but only when it is placed inside a fuller picture of how work flows.

What a "line" is, and why definitions matter

A line is usually one SKU on an order. If an order has three SKUs, it has three lines. If one line requires one unit, it is a simple line. If a line requires ten units, it is still one line but it is more work. Before you compare lines picked per hour across teams or across days, you need a consistent definition and a segmentation strategy.

If you do not segment, you will punish the team handling complex orders and reward the team handling easy singles. That is not measurement. That is noise dressed up as fairness. A strong program tracks lines picked per hour by order profile, by zone, and by item characteristics like size, weight, and hazard classification, because a HAZMAT pick and a small apparel pick are not the same kind of work.

Why lines picked per hour should be tied to SLAs

A warehouse exists to meet service levels, not to win a picking contest. Joel Malmquist, VP of Customer Experience at G10 Fulfillment, described the SLA scope in a way that keeps productivity metrics grounded. "An SLA is a Service Level Agreements for Receiving, Outbound, and B2B." That matters because outbound picking can look productive while the business still misses SLAs due to receiving delays, pack station constraints, or B2B compliance work.

For D2C, the SLA is often a same-day cutoff, which makes picking speed important but not sufficient. Malmquist described the cutoff in direct terms. "For D2C, which is an order through Shopify or on the merchant's website, if it's before noon, we're going to ship that order the same day." If you want that promise to hold, lines picked per hour has to be balanced with pack capacity and carrier handoff timing, or you will pick quickly and still miss the day.

Why accuracy must sit next to productivity in every report

Lines picked per hour can rise by cutting corners. If a picker skips scans or rushes through lookalike SKUs, output goes up and errors go up. Those errors then create reships, returns, inventory drift, and support tickets that eat the labor savings. This is why productivity metrics are dangerous when they are reviewed alone.

Malmquist described the kind of accuracy that is hard to achieve without disciplined scanning and verification. "We have over 99.9% ship accuracy of these orders, which when you look at it on a unit level, such as unit shift versus unit errors, I almost couldn't believe it when I came here, how well we're doing on B2B shipping." That level of accuracy suggests that productivity is being managed with quality controls, not by pushing people to move faster at any cost. A strong picking program pairs lines picked per hour with pick accuracy, exception rates, and rework rates, so productivity gains do not turn into hidden damage.

How travel time quietly controls lines picked per hour

Pick productivity is usually limited by walking. If the warehouse layout forces long travel between picks, lines per hour will be capped no matter how motivated the team is. That is why slotting and pick path design are some of the highest leverage improvements you can make.

Travel time is also why segmentation matters. A zone pick model can boost lines per hour by reducing walking, but it can also increase touches and handoffs. Batch picking can increase lines per hour for small items, but it can create congestion and errors if pack stations cannot absorb the flow. The goal is to measure the whole chain, not only the pick step, because a faster pick step can overwhelm the next step and create more total time.

Replenishment health is the silent factor behind productivity drops

When pickers cannot find product in a location, lines per hour drops. The easy story is that the picker is slow. The true story is often that replenishment was late, inventory accuracy drifted, or receiving did not get inventory stowed fast enough. In other words, picking productivity depends on upstream discipline.

Malmquist described receiving timing in clock terms that show why upstream flow matters. "For receiving, the SLA is covers the time from the moment that we get a container on the dock with inventory in it, and how much time we have to count that in, and stow it away into the locations that we're going to pick from." If receiving is slow, replenishment becomes unpredictable, and pickers spend more time waiting and searching, which depresses lines per hour. A good picking productivity report therefore includes replenishment completion times and location stockout rates, because those metrics reveal whether the pick team is being set up to succeed.

Why scan-based tracking makes lines per hour a real metric

If your lines per hour metric is built from manual updates, it will eventually become a debate. Scan-based events are what keep the metric grounded in reality. They also allow you to analyze the data in ways that lead to real improvements: which zones are slower, which SKUs create exceptions, and which shifts have higher rework.

Bryan Wright, CTO and COO of G10 Fulfillment, described the foundation of trustworthy warehouse data. "A good WMS tracks inventory through the warehouse at every point that you touch it." He explained why that matters on the floor. "At any point in time, I know that Bobby has this product on fork 10 right now, and if I needed to go find that product, I just got to go find Bobby on fork 10." Scan-based tracking allows you to measure lines per hour, investigate exceptions, and improve slotting and replenishment with evidence instead of anecdotes.

Why the definition of "shipped" still matters for picking metrics

Picking productivity is only valuable if it contributes to shipped orders on time. If picking finishes quickly but orders sit staged waiting for pickup, the customer experience still feels slow. This is why a pick report should be reviewed alongside carrier handoff timing, especially for same-day promises.

Malmquist explained the gap that can confuse reporting. "The reason I don't say ship is because sometimes it will be marked as completed, but the carrier doesn't actually pick it up right away, but the tracking goes back to Shopify." If your operation celebrates high lines per hour but ignores the completion to acceptance gap, you can feel productive while customers feel stuck. A mature reporting practice tracks the whole chain: pick completion, pack completion, stage completion, and carrier acceptance.

How to improve lines picked per hour without turning the warehouse into chaos

The best improvements usually come from system design, not pressure. Slotting optimization reduces travel time. Zone picking or wave planning reduces congestion. Better replenishment timing prevents location stockouts. Clear exception workflows keep pickers from getting stuck. Training on lookalike SKUs and scan discipline reduces rework.

Most importantly, improvement should be tested and measured. If lines per hour rises but pick accuracy falls, the change failed. If lines per hour rises and accuracy stays stable, the change is real. That is the difference between productivity and haste.

Where G10 fits if picking productivity needs to support growth

Lines picked per hour is a useful metric when it is tied to service levels, accuracy, and real warehouse events. G10 focuses on scan-based execution, inventory traceability, and customer-facing visibility so productivity is measurable and actionable. As Wright said, "A good WMS tracks inventory through the warehouse at every point that you touch it." That tracking supports fair measurement, faster root cause analysis, and improvements that do not sacrifice quality.

If you want to see how picking productivity is measured in practice, ask for a walkthrough of a live day in the portal that shows lines per hour by zone, pick accuracy, and the downstream impact on pack flow and carrier handoff. You should be able to trace how a productivity improvement changes the full order cycle, so you can grow without turning the warehouse into a permanent sprint.