The date that looks safe
A courier owner, paid by business customers per completed delivery, wants a stable estimator to confirm dates and eliminate repeated checks. Consistent predictions make this tempting. Yet predicting arrival does not reserve delivery capacity. A wrong confirmation can leave a customer waiting with staff ready, while the dispatcher scrambles to offer a date the business can keep.
In this hypothetical example, 24 orders await confirmation and the dispatcher has 60 minutes to check them. Every quantity below is assumed, not a reported result.
The missing commitment
One order shows “estimated_date: today.” The estimator uses normal travel time but omits jobs already assigned to the vehicle. The live schedule shows “remaining_slots: 0.” Confirming today would promise capacity already committed, even with a perfect travel prediction. Comparing the records exposes the conflict; the dispatcher withholds confirmation and offers a date with capacity. The customer receives the reserved date, while the original estimate remains visible for comparison.
Two ways to protect today's promises
Reviewing and reserving capacity for every order takes two minutes each: 24 × 2 = 48 minutes, within the 60-minute limit.
Alternatively, allow 12 minutes to reconcile bookings with vehicle capacity and reserve routine jobs, then two minutes per exception. With six exceptions, 12 + (6 × 2) = 24 minutes. Choose this approach when the reconciliation accounts for every booking and blocks conflicting promises; it leaves 36 minutes available.
Check before the customer hears yes
Match booking references and assigned dates between the booking list and live schedule. A missing booking or unexplained difference stops selective review: refresh, then use full review if it persists. For reconciled records, zero free slots blocks that date; reserve capacity before confirming. After reconciliation, a full-review fallback takes 12 + 48 = 60 minutes.
When the backlog reverses the choice
Now a backlog raises exceptions to 18. Selective review takes 12 + (18 × 2) = 48 minutes, matching full review. At 18 or more exceptions, use full review; below 18, use selective review only after the capacity check passes.