How do I evaluate a WMS for my 3PL?

Most founders are taught a version of this: list your requirements, demo a few vendors, check references, decide. The steps aren't wrong. But the inputs they depend on are.

Requirements lists reflect what you believe your operation needs, filtered through proximity blindness to your own floor. The workarounds, exceptions, and process gaps that actually define how the operation runs have become invisible. You stopped seeing them years ago. Vendor demos respond to the mental model you describe, not the floor reality where fit problems live. References are vendor-provided, vendor-prepared, vendor-incentivized. The unhappy clients don't show up.

Every input that feels like due diligence was shaped by someone with a stake in the outcome.

A real evaluation has to fix the inputs before the process begins. That means a documented operational baseline that proximity didn't filter — what's actually happening on the floor, not what you'd describe in a meeting. A shortlist filtered by operational fit, not by which vendors were visible and recommended. Vendor evaluation run through a frame that exposes what a buyer-only frame structurally misses, because vendors are designed to be evaluated by buyers.

More effort doesn't close those gaps. More research, longer demos, more reference calls — they generate more volume of the same compromised inputs. The conventional process produces a selection built on a foundation you can't see clearly from inside it. The way to evaluate a WMS well is to recognize that, and fix what the process depends on before any vendor conversation begins.