Here's the uncomfortable truth about WMS demos: they are theater. Rehearsed, scripted, choreographed theater. And most buyers walk out of the theater, sign a contract, and then spend the next year wondering why the software that looked so effortless on a projector screen falls apart in their warehouse.
I watched this happen in 2019 with a home-goods distributor outside Los Angeles. The demo was flawless — scan a barcode, waves release instantly, pick paths optimized like a textbook diagram. The owner signed on the spot. Nine months later, go-live week, the warehouse was sitting on 6,000 backlogged orders and the owner was yelling at me across the dock: "It worked fine in the demo!"
Of course it did. That was the point.
Three demo tricks to watch for
First, sanitized data. The demo database holds maybe 500 perfect SKUs — every item barcoded, every lot clean, every slot assigned. Your warehouse has 20,000 SKUs including the ones with missing barcodes, crushed cartons, and three lots mixed on one pallet. The software looks fast because it has never met dirty data.
Second, the happy path. Sales demos always walk the golden road: receive, putaway, pick, pack, ship. Ask about returns processing and you hear "it's configurable." Ask about serial-number traceability and you hear "we support that." Those two words — configurable, supported — routinely translate into a second invoice for custom development during implementation. Ask them to run your actual returns flow live, on the spot. Most won't.
Third, the wrong operator. The person demoing is usually a pre-sales engineer or a senior implementation consultant who could operate the system blindfolded. The team that actually implements your project will be different people — possibly consultants three months out of training. How smooth the demo feels has almost nothing to do with how good your implementation will be.
Take the script away from the vendor
A real POC has one principle: the buyer writes the script.
Write yours before the vendor touches anything. Cap it at about ten scenarios, all pulled from orders your warehouse actually processed in the last three months. My recommended list: standard receiving and putaway, full-pallet receiving with damage, rush order wave insertion, short-pick reallocation, serialized item returns, broken-pallet replenishment, cycle-count variance adjustment, relabeling. Attach real data — at least 2,000 of your actual SKUs including the ugly ones — plus one real week of order volume.
Then set the ground rules: no pre-loaded vendor data, they import yours on the spot; the operator must be your warehouse supervisor, not their consultant driving the mouse; every scenario gets timed.
That "no hand-holding" rule matters most. I have sat through POCs where the vendor's consultant stood behind the operator narrating every click, practically moving the mouse for them. That tests the consultant, not the software. Put your least tech-savvy supervisor in the chair. If they can learn it in the session, the system is usable.
Quantify the pass line or don't bother
When the POC wraps up, never ask the room "how did it feel?" Feelings are the worst acceptance criteria ever invented.
Write the pass criteria on page one of your POC script and get the vendor to sign it. For example: at least seven of eight scenarios completed end-to-end with zero vendor assistance; wave release of 500 orders completes in under two minutes; a cycle-count adjustment takes no more than five clicks; your supervisor operates independently for two hours without an error.
Miss the line? Two options: the vendor admits it needs custom development and puts the scope and price in writing, or they're out. The phrase to fear is "we'll look into that" — it means "it doesn't work today."
One trap I should call out specifically: the guided tour. Some vendors will run your scenarios for you — their consultant drives, your people watch — and call that a POC. That's a demo with your logo on it, not a proof of concept. If the vendor's hands are on the keyboard more than your team's, stop the session and reset the rules. A POC where the buyer never touches the software proves nothing except that the vendor can operate their own product, which was never in doubt.
One more move: bring your IT lead to the POC and have them evaluate the integration layer. Your WMS will talk to your ERP, your TMS, your e-commerce platforms. Half a day is enough to tell whether the API documentation is real and whether a sandbox environment exists. Ask for the API rate limits too — a system that throttles you to a few hundred calls an hour will choke the moment your order volume spikes. A system with rotten interfaces will drag your implementation into the ground.
Three questions before you sign
The POC passed. Before the contract, get these three answers in writing as a contract exhibit.
One: for every scenario that passed the POC, who pays for custom development if it doesn't work at go-live? Many contracts quote implementation as an "estimate" with overages billed separately. Attach the passed-scenario list as acceptance criteria — if it doesn't work, that's the vendor's problem.
Two: who exactly is on the implementation team? Get the lead consultants' names in the contract, with a clause that replacements need your approval. Verbal promises of "our best team" are worth nothing.
Three: response times for the first 90 days post-go-live. Something will break — the question is how fast they show up. Write it down: remote engagement within four hours for critical issues, on-site within 24.
That home-goods customer? They switched systems. The second selection round, I made them run a three-week POC with real data and over 200 real orders. Go-live day on the new system, the warehouse closed out with two hours of overtime. The owner told me later he wished they'd done it that way the first time.
A POC is the only moment before signing when you can make the vendor do real work. Don't waste it.
