Distribution centers running manual or traditional automated sortation often struggle to scale beyond their current capacity without major infrastructure changes. Peak season often demands 4x normal capacity, but scaling with temporary labor has become increasingly expensive and unreliable. This guide examines three common scenarios:
Scaling fixed conveyor systems (where adding induction points cuts destinations in half)
Manual operations that can't staff up
Modular AMR approaches that reach 22,500+ sorts/hour without expanding footprint
The key insight: throughput constraints aren't about equipment speed—they're about destination capacity, accuracy under pressure, and labor availability during peak demand.
Your automated sorter runs all day. During peak periods, you're hitting rated capacity, but orders still back up. You're looking at options to increase throughput without building another facility.
Option 1: Speed Up the Conveyor
The most obvious solution is changing the gearbox to run faster. If you're processing 10,000 sorts per hour and need to reach 20,000, just double the speed, right?
Not quite. You can increase the items moving through the system, but if you still have 200 destinations, you're just dumping more volume into the same 200 spots. Throughput increases, but destination capacity stays flat. You get more items per hour flowing to the same limited number of sort points.
The constraint shifts from the sorter to the chutes. They fill faster. Workers can't keep up with container swaps. Items start recirculating because destinations are full. That recirculation wastes 10-20% of your capacity and creates accuracy problems as packages get scanned multiple times.
Option 2: Add Another Induction Point
Loop sorters can technically add a second induction station to double capacity. You induct on one end, items discharge on one side. Then you add another induction on the opposite curve, and those items discharge on the other side.
Here's the reality: "Loop sorters will tell you, oh, we can add another induction station and increase capacity. What they don't tell you until you dig deeper is if you do that, you just cut your effective destinations down per batch."
You cut your destinations in half. Each induction now serves roughly half the destinations. "Now I'm picking a smaller batch, going to a separate induct, and it becomes a more difficult process to control."
The problem compounds with recirculation. "Anything that doesn't get off is a lost destination capability on the other side because it's got to go all the way around now." Items that miss their discharge point on the first pass block that destination spot for new items while they loop back around.
You doubled raw throughput but halved usable destinations per batch. For many operations, that trade-off makes the system harder to manage, not easier.
Option 3: Supplement with Manual Put Walls
When automated systems hit capacity, many operations add temporary manual put walls during peak season. You take a sort chute and send 50 orders down it instead of one. Then workers manually sort those orders into individual slots on a put wall.
This approach adds capacity quickly. You can staff it with seasonal temps and scale up for a few months. But the cost structure changes dramatically.
Manual sortation runs 5x more expensive per unit than automated processing. Your accuracy drops from 99% down to 93% or worse, especially with new temp workers who walked in the door last week. Error rates climb from 1.5% to 7% during peak periods as people rush to keep up.
You just destroyed the accuracy advantage your automated system provided. Customer orders get mixed up. Returns increase. And you're burning margin on labor costs during the highest-volume period of the year.
What Actually Works: Understanding System Limits
High-volume facilities typically don't exceed 50,000 sorts per hour. "At 20 hours a day, that's a million units a day. And you read once in a while about a building that's doing a million units a day. And typically, they're going to have multiple tilt trays or sorters in that building. So they're huge operations…it's very seldom you hear of a building or fulfillment building doing more than 50,000 an hour."
The throughput number matters less than destination capacity. A system processing 50,000 sorts per hour with only 200 destinations creates massive downstream bottlenecks. You need proportional growth in both metrics.
Loop sorters and tilt trays face physical constraints. They often operate at 50-70% of rated capacity in real-world conditions because downstream handling can't keep pace. The automation runs fast, but manual processes after sortation create the bottleneck.
Manual operations scale by adding people. Need to double throughput? Add more workers and more put wall slots. It's straightforward until you try to staff for peak.
Peak season often requires 4x normal capacity. That means 4x the workers. But warehouse positions have 65% vacancy rates right now. You can't hire fast enough. The labor doesn't exist in the market.
Even if you could hire enough temps, their accuracy is worse than your experienced staff. Someone who's been with you for six months to five years knows the process. A temp who started yesterday makes mistakes.
Manual put walls during peak mean you're running the most labor-intensive process at the highest-volume time with the least experienced workers. Accuracy suffers. Speed drops. Orders slip.
The Cost Per Unit Reality
Manual sortation costs 5x more per unit than automated processing. That multiplier includes labor, error correction, and slower cycle times.
If your margins are thin, you can lose all your profit on the extra spend during peak. You're generating revenue but burning it on inefficient fulfillment operations.
The Delivery Promise You Can't Keep
Take an example from apparel retail. We worked with a children’s apparel retailer who was "notorious for the longest time of turning orders within two days and giving free shipping if you had a certain dollar amount." Their average e-commerce order ran eight and a half pieces because customers ordered multiple low-cost items to hit the free shipping threshold.
During peak season—Black Friday through Cyber Week—their manual system couldn't scale. "That two-day turnaround time at holiday Cyber Week, it would take up to 10 days to get the orders out the door which upset their customers."
They were "horribly missing the expectations of all the parents out there who were ordering this stuff for bargain deals on Black Friday and Cyber Week."
That's not just an operational problem. It's a customer experience failure that shows up in repeat purchase rates and lifetime value. "It's delivery speed, it's cost, and it's accuracy."
Autonomous mobile robots handle sortation differently than fixed conveyors or manual systems. Instead of moving items along predetermined paths, robots carry products on trays and navigate dynamically to sort destinations.
Starting Range and Flexibility
AMR sortation systems begin around 2,000-3,000 sorts per hour. That's viable for mid-sized operations that need automation but don't have the volume to justify massive loop sorters.
The lower entry point matters because you can start smaller and add capacity incrementally. You're not building infrastructure for peak volume that sits underutilized most of the year.
Scaling to High Performance
The same technology scales to 40,000+ sorts per hour for large operations. You add robots instead of building new conveyor loops. Deployment happens in days or weeks, not months of construction.
Systems can handle 1,200+ sort destinations without the footprint of traditional sorters. You're not constrained by physical chute arrays or conveyor geometry. The robots navigate to wherever you need them to deliver items.
Adding Capacity Without Adding Square Footage
Traditional sorters require linear space. A loop sorter with 200 chutes needs hundreds of linear feet for the chute array, plus staging areas, plus access aisles for forklifts. The footprint grows with capacity.
AMR systems operate in the same floor space regardless of throughput. Adding capacity means adding robots, not expanding the building. You maximize throughput per square foot instead of requiring more square footage for throughput.
Time to Deployment
Fixed conveyor systems require permits, electrical work, structural installation, and commissioning. That timeline runs months, sometimes over a year for complex systems.
AMR fleets deploy in days to weeks. You map the facility, set up charging stations, integrate with your WMS, and start operations. No heavy construction. No permits for fixed infrastructure.
The system you install handles both normal and peak volumes without adding temporary labor. Instead of staffing 4x workers during peak season, you build permanent capacity that scales to demand without the hiring constraints that cap manual operations.
The top tier of distribution center operations processes 40,000-50,000 sorts per hour. At that scale, you're moving one million units per day over a 20-hour operational window.
Destination Capacity Matters as Much as Throughput
A system that sorts 50,000 items per hour but only has 200 destinations creates bottlenecks. You need proportional growth in both metrics.
High-performance systems handle 6,000-10,000 sort destinations. That allows fine-grained routing without downstream congestion. Items flow to specific staging areas, shipping lanes, or store routes without batching delays.
Real-World Example
CVS operates a Tompkins Robotics tSort system that processes 22,500 sorts per hour using approximately 720 robots handling 1,200 destinations. That's a working example of throughput, destination capacity, and floor space efficiency combined.
The system runs continuously without the single-point-of-failure risk of loop sorters. If one robot needs service, the other 719 keep working. There's no choke point where a jam stops the entire operation.
To see the full case study, click here.
No Single Point of Failure
Traditional loop sorters and tilt trays create dependency. If the main belt stops, nothing moves. A jam at one point backs up the entire system.
Distributed systems using multiple autonomous units eliminate that constraint. Individual robots can be serviced without stopping operations. The fleet routes around maintenance windows and adapts in real time.
Your path to increased throughput depends on where you're starting and what constraints you face.
Questions to Answer First
How many sorts per hour do you need during peak vs. normal operations? What's the gap between those numbers? That spread determines whether you need flexible capacity that scales temporarily or permanent infrastructure.
How many destinations do you need to support? If you're routing to hundreds of stores or thousands of individual orders, destination capacity matters more than raw throughput. Adding speed without destinations just creates different bottlenecks.
What's your hiring reality during peak season? If you can staff 4x normal headcount with reliable workers, manual solutions might work. If labor scarcity limits growth, automation becomes necessary rather than optional.
When to Supplement vs. Replace
If you have automated sorters running below 50% of capacity, optimization might solve the problem. Look at downstream handling, staging area flow, and destination management before replacing equipment.
If you're at 70%+ utilization with no room to expand destinations, supplementing with flexible automation makes sense. You preserve existing investments while adding capacity that scales independently.
If your current system can't grow meaningfully without major construction, replacement becomes the practical option. Modular systems that deploy quickly and scale incrementally offer better return than doubling down on fixed infrastructure.
Peak Season Planning That Works
Peak demand will hit whether you're ready or not. Planning around impossible hiring targets doesn't work.
Build capacity that scales with demand instead of depending on 4x labor increases. That might mean modular automation that adds robots during peak. It might mean hybrid systems where automation handles base load and strategic manual processes fill gaps.
The goal is hitting SLAs and maintaining delivery promises and accuracy during high-volume periods without destroying margins on labor costs.