The need for adequate sampling in a well-functioning market surveillance system

Current regulatory requirements for products emphasize more on faster access of products to the market while at the same time increasing post-market or market surveillance actions. Doing this way the cost of market surveillance actions are increasing and therefore market surveillance shall be more carefully planned to keep costs reasonable. In this regard, adequate sampling is essential for the well-functioning of a market surveillance system. As small as possible statistically significant sample size is the main factor that determines the costs of market surveillance actions. This paper studies various possibilities for calculation of the size of the sample with an emphasis on the method based on the binomial distribution. Examples, comparisons, and conclusions are provided.