Last post was a discussion on the types of examinations. The question presents itself: Whose shipments will be inspected? The term one will hear is that examinations are random. However, determination for inspection of merchandise is by majority controlled by a automated system which is overseen by human judgment. Generally, Customs will inspect more shipments of an importer who has a history of poor compliance. Other factors may include, the familiarity with the importer, type of goods being imported, and the foreign factories being used to manufacture the merchandise.
In addition, Customs periodically targets for examination certain Harmonized Tariff numbers to determine compliance on a nationwide level. If the importer finds themselves being checked more than a few times by Customs it is best to investigate the matter, other issues may be at play.