Human-in-the-Loop Is a Queue, and Queues Have Dynamics
Teams add human approval to an AI workflow the same way they add if (isDangerous) requireHumanApproval() to a codebase: as a binary switch, checked once at design time, then forgotten. The metric on the architecture diagram is a green checkmark next to "human oversight." The metric that actually matters — how long the human took, whether they read anything, whether the item was still relevant by the time they clicked approve — rarely has a dashboard.
Treat the human approver as a binary switch and you have built a queue without knowing it. And queues have dynamics: backlog that grows faster than you staff, staleness that makes yesterday's decision meaningless, fatigue that turns review into rubber-stamping, and priority inversion that parks the one decision that mattered behind three hundred that didn't. None of this is visible in the architecture diagram. All of it shows up in the incident retro.
