Warehouse Management Systems: What to Expect From Your 3PL's WMS

A warehouse management system (WMS) is the software that tells a warehouse where every unit sits, which order to pick next and what has shipped. If a 3PL ships your orders, you don't buy one: your orders already go through the 3PL's system. So when a brand researches warehousing management systems, the useful work is checking what that system gives you, from live inventory and order status to lot tracking and the scans that stop a wrong item from shipping. KSP's ecommerce fulfillment uses the Logiwa WMS (which clients love for its ease of use), and your storefronts and marketplaces connect to it through a prebuilt connector, the open API or EDI.

What is a warehouse management system?

A WMS is the record of everything physical in a warehouse and the instructions for moving it. Every unit has a location, every location has a barcode, and every move gets scanned so the count stays true. The system covers the full life of your inventory in the building:

• Receiving. Inbound cartons and pallets are counted and scanned against what you said you sent, then stock becomes available once it's counted.
• Putaway and locations. Each SKU is assigned to a bin, shelf or pallet position, and the WMS knows how many units are in each one.
• Inventory. On-hand, allocated and available counts by SKU, plus lot and serial numbers where the product needs them.
• Picking. The WMS sends each order to the floor and tells the associate what to pick and from where.
• Packing and shipping. Packed cartons are weighed and measured, labels print, and tracking goes back to the channel that sold the order.
• Returns. Returned units are checked in and either restocked or set aside, and the count updates.

A WMS tracks inventory and orders. It doesn't plan labor hours, book dock appointments or track floor projects and internal IT requests. Warehouses keep that work in separate tools, and sometimes in bare spreadsheets. In our building we use KSPHQ from our sister brand KSP Technologies, which sits beside the WMS and covers labor time, dock doors, floor projects and internal requests. If you operate your own warehouse and you're shopping for software, that split is worth knowing before you compare WMS vendors.

Do you need your own WMS if you use a 3PL?

No. You need visibility into your 3PL's WMS, and you get it two ways: the 3PL's client portal and the integration between your store and the warehouse.

The warehouse keeps track of locations, pick paths, labor and carrier labels inside its WMS. Your store, marketplaces and ERP stay the record for sales, customers and refunds. The integration moves four things between them: orders into the warehouse, tracking back to the channel, inventory counts back to every storefront, and receipts for the stock you sent in.

Buying your own WMS on top of that only makes sense if you also manage a building of your own, such as a stockroom that ships wholesale orders while the 3PL ships DTC. Even then, the two systems need to agree on one count, or both channels oversell.

What should your 3PL's WMS show you?

Your 3PL's WMS should answer the questions you'd otherwise email the account manager about. Ask to see each of these in the portal or in a report before you sign:

• Inventory by SKU. On-hand and available-to-sell, with units already allocated to open orders taken out. If you sell on several channels, every channel should draw from the same count.
• Inventory by lot. For supplements, cosmetics and food, you need the units on hand for each lot and its expiration date, and a rule for which lot ships first.
• Order status. Each order's stage from received to shipped, the tracking number, and the reason for any hold.
• Receiving results. What arrived against what you sent: shortages, overages and damaged cartons, reported the day the shipment is counted.
• Returns. Which units came back, in what condition, and whether they went back into stock.
• Reports you can export. Inventory snapshots, shipments by day and order history in a file your finance team can open.

Held orders deserve a separate look. A good WMS stops an order it can't match, such as an unknown SKU or an unmapped bundle, instead of shipping something close. You want to see those holds the day they happen, with the reason attached.

KSP clients log into an online portal to see orders, inventory and shipment status. Where your product needs it, serial and lot numbers are scanned in the WMS, which matters most for electronics, warranty claims and returns. The details are in our guide to tracking serial numbers through a 3PL.

How does a WMS handle lots, expiration dates and recalls?

If you sell supplements, cosmetics, gummies or packaged food, lot tracking is the part of the WMS you'll lean on hardest. Receiving has to capture each lot number and expiration date as the stock comes in, and every pick afterward has to record which lot went into which order. Without that record, a short-dated case can sit behind fresh stock until it expires, and a recall means pulling every unit of the SKU.

Three questions tell you whether a 3PL's WMS handles lots properly:

• Does it pick by expiration date? The usual rule is first-expired, first-out (FEFO), so the units closest to their date ship first. Ask whether the WMS enforces the rule on every pick or leaves it to the associate.
• Can it hold a lot? If you quarantine a batch for a quality issue, the WMS should block those units from being picked while the rest of the SKU keeps shipping.
• Can it trace a lot to orders? For a recall, you need the list of orders and customers that received a specific lot, pulled from the WMS rather than rebuilt from packing slips.

Lot tracking records which units shipped, but heat damage happens on the shelf. KSP stores inventory in a climate-controlled, FDA-registered building, so gummies and creams received in July are still in spec when the last unit of the lot ships.

How does a WMS keep orders accurate?

A WMS keeps orders accurate by refusing to let a step finish until the scan matches what it expects. Inside KSP's building, our QA process goes in this order:

1. The order is checked against your SKU map. Each line has to match a stocked SKU. An unknown SKU, an unmapped bundle or an out-of-stock line is held for correction.
2. The tote is scanned. The pick is tied to one container, so items from two orders don't mix.
3. Each unit is scanned. The unit barcode is checked against the order. A wrong item doesn't register, and the associate has to fix it before the order moves on.
4. The carton is weighed and measured. Packed cartons pass certified scales and dimensioners before the label prints, and those numbers feed carrier rate shopping.

Bundles and kits get one more layer. A bundle that sells as one storefront SKU is mapped to its components in the WMS, so a single order draws down the right parts. Prebuilt kits are checked against their bill of materials before they're sealed. If you sell gift sets or subscription boxes, our kitting and assembly floor builds them in the same building that ships them.

Those checks are why KSP maintains a 99.999% order accuracy across 32.1M orders, counted on whole orders shipped right.

What should you ask a 3PL about its WMS?

Ask these before you sign, and ask for answers in writing:

1. Which WMS do you use? Get the name. A 3PL that can't tell you, or tracks orders in spreadsheets, will struggle to give you live inventory.
2. How does it connect to my store, marketplaces and ERP? A prebuilt connector, an API or EDI each fits a different setup. Ask who watches for failed orders on each side.
3. What does the client portal show? Ask for a walk-through with a live account: inventory, order status, holds, receiving and returns.
4. How often does inventory sync to my channels? The answer depends on the connector, so ask per platform, not in general.
5. When does received stock become sellable? It should be when it's counted and put away, not when the truck is booked.
6. Do you track lots, expiration dates and serial numbers? If your product carries any of them, ask how each is scanned and how a recall would be pulled.
7. What happens to an order the WMS can't match? The order should stop with the reason recorded, and your account manager should tell you the same day.
8. How long does setup take? Most of the time goes into SKU and bundle mapping, not the connection.

Here is how KSP answers the ones that change the decision:

• System: Logiwa WMS, connected to Shopify, Amazon, Walmart, BigCommerce, WooCommerce, Magento, eBay, TikTok Shop and Faire through prebuilt connectors, plus NetSuite, QuickBooks, CommerceHub and ShipStation. Retail EDI goes through our SPS Commerce partnership.
• Setup: a simple Shopify connection takes as little as 20 minutes, and our in-house tech team handles most custom builds in under a week. Sync timing is confirmed per platform during onboarding.
• Speed: orders in by 2 PM CST ship the same day, and an order gets picked and packed in under 30 minutes.
• Accuracy: 99.999% order accuracy across 32.1M orders and 99.95% shipping accuracy.
• Floor: more than 135 Locus robots carry order containers through picking, so associates spend their time picking and scanning.
• Storage: climate-controlled, FDA-registered space with 29 dock doors.
• Support: a 2-hour response SLA when something goes wrong with an order.

Frequently asked questions