The check of conformity with the purchase documents must be done at the distributor’s warehouse, while on the job-site, the panels must be inspected prior to installation, to make sure the board type and dimensions comply with the intended application.
This means to confront the marking from the product / label with the documents of origin and with the product data sheet.
Visual inspection is merely meant to identify and conclude rapidly upon the total quantity of mist-delivered and/or damaged product (having crashed edges/corners from transport or unloading), rather than to evaluate the product quality.
This can only be done in laboratory conditions, following the testing procedures given in standards.