Choose representative and difficult samples
Include minimum and maximum dose, highest and lowest viscosity or temperature, largest particles, highest foam risk, lowest powder bulk density, least stable container and packaging from more than one supplier batch where variation matters.
Define measurable acceptance criteria
State sample size, measurement method, tolerances, sustained run time, accepted output, pack-cleanliness limits, closure or seal tests, label position, code quality, reject response, changeover time and cleaning observations before the trial starts.
Test the complete intended route
Product feed, filler, capper or sealer, labeller, coder, inspection, reject handling, conveyors and accumulation interact. A standalone filler trial does not prove the integrated line rate or pack quality.
Record settings and deviations
Retain product and pack batches, machine recipe, filling-head results, line speed, temperatures, vessel level, interventions, rejects, photographs or video and unresolved actions. Evidence should be clear enough to create or refine the FAT protocol.
Plan what must be repeated on site
Utilities, room conditions, bulk transfer, final guarding, upstream product process, downstream handling and operator methods may differ from the supplier trial. Define a site acceptance test for those remaining conditions.