How should weighing error be defined as an acceptance criterion for an automatic packaging machine?

Use standard weights and real product across the target range, separating static weighing error from continuous packing error. For a fair comparison, keep raw material, batch size, speed, and environmental conditions consistent across suppliers. For export projects, confirm the utility conditions and installation requirements before the supplier starts final assembly. Any later change to the tested configuration should be documented and, when necessary, verified again before shipment. If the process is sensitive to raw-material variation, include defined material limits in the specification and acceptance protocol.