What WMS selection mistakes lead to failed implementations?

If you're mid-evaluation, the patterns that produce failed implementations are likely visible in your current process right now. Three are typical.

The first: your requirements document captures what you and your team can articulate when asked directly. The workarounds nobody questions anymore, the exceptions that have become routine, the process gaps people have built habits around — those are the things most likely to break under a new system, and they're the things least likely to show up in a requirements doc you wrote. Proximity blindness is operating on you in real time. The vendors responding to your requirements are responding to the operation as you described it, not as it actually runs.

The second: your shortlist is shaped more than you realize by which vendors were visible and recommended. Availability bias is the dominant filter when founders haven't done documented operational work first. The vendors you're demoing got there because peers mentioned them, because they showed up in search, because they reached out at the right moment. Those filters predict visibility, not fit. The fit-relevant question — which of these vendors can actually support how this specific operation runs — gets answered by elimination during demos rather than by selection upfront, which is the opposite of what produces a defensible decision.

The third: the questions you're asking in demos feel rigorous, and they are. They also come from inside the same frame vendors are designed to satisfy. The polished demo answers feel reassuring because they're calibrated to feel reassuring. The follow-up questions that would catch strategic omission come from the side of the table the buyer has never sat on.

These aren't future risks. They're the conditions of your evaluation right now. The implementations that fail twelve months from now are the ones where these patterns ran unchallenged through selection.