Deliver the decision in time
Sortation combines identification, destination selection and local actuation. Define where identity becomes available and the latest point for receiving the decision. Local timing belongs to the appropriate controller; WCS should not require a network round trip for each actuation instant.
Relate distance and speed to the worst acceptable decision delay. Include reading, processing, communication and margin. Low average latency does not prevent peak-delay failures.
Availability includes reservations
Destination eligibility may include occupancy, shipping assignment and station availability. Loads already released consume capacity before sensors report their arrival. Several decisions based on one stale free-space observation can oversubscribe a chute.
Specify the commitment point. Changing a recorded destination after the physical decision point can make logical tracking disagree with the route actually taken.
No-read and recirculation
Unidentified loads require an explicit exception or identification process. Reusing the previous load identity to maintain flow creates misdelivery risk. Record recirculation reason, attempts, limits and final exception destination.
Recirculation consumes main-line capacity. Higher induction with blocked destinations can increase occupancy without increasing useful deliveries. Measure causes and resolution time.
Worked timing budget
An illustrative 6 m at 2 m/s gives 3 seconds between points. This is not an SLA: reading, processing and margins still consume the budget, and real geometry may require a different model. Vary speed, delay and chute availability in testing.
Acceptance checks correct destination per load, late decisions and exception routing. Report latency percentiles, rejections and useful deliveries; nominal passages are not shipping capacity.
Project verification criteria
- Measure the actual identification-to-decision window.
- Inject no-read, closed destinations and delayed messages.
- Verify bounded recirculation and load-level traceability.
Examples describe engineering decisions and test scenarios. Implemented interfaces, limits and features are defined by each project’s scope.