Why do WMS implementations fail?

Most explanations of WMS implementation failure focus on the implementation phase: change management was weak, the project plan slipped, the integration was harder than expected, training didn't take. Those things are real. They're also rarely the cause.

Most "implementation failures" are selection failures showing up downstream.

By the time an implementation is in trouble, three things have usually been true for months. The system was selected against an inaccurate picture of how the operation actually runs — a picture filtered through proximity blindness, where the workarounds and exceptions that define daily operations had become invisible to the founder before the requirements conversation ever started. The shortlist was shaped by which vendors were visible and recommended rather than which vendors fit — availability bias dressed up as due diligence. And the vendor evaluation was run through a buyer-only frame, which is the only frame vendors are designed to be evaluated by, which means the questions that would have surfaced fit problems weren't asked.

None of those gaps are visible during selection. They become visible during implementation, when the operation that wasn't fully documented meets a system that was selected for the operation's described shape rather than its actual one. Workflows the founder didn't surface as requirements run into system limits. Customizations the vendor implied would be straightforward turn out to require services-team work the contract didn't price. Edge cases nobody flagged become the cases that break first. The implementation team is now solving a fit problem in real time, after contracts are signed, when the cost of changing course is highest.

The pattern is consistent enough that the conventional explanation gets the causation backwards. Implementation isn't where the failure happens. It's where the selection failure becomes legible.