Sample Size Code Letter
Meaning ~ Alphanumeric identifier from standard tables that dictates the minimum number of units required for inspection based on the total lot size and level selected.
Sample Quantity
Meaning
Number of individual units drawn from a larger population to be tested during a quality inspection. Determination of the sample quantity is based on statistical tables that balance the cost of testing and the need for a high level of confidence in the results. This figure must be large enough to represent the entire lot but small enough to be manageable for the inspector.
Selection Process
Units must be taken from different parts of the batch to ensure the data is not biased toward a single production window. If the sample quantity is too low, the probability of missing a serious defect increases significantly, which exposes the buyer to financial risk.
Time Management
Hours required for a pre-shipment audit are directly proportional to the number of items that need to be checked. Planning for an adequate sample quantity ensures that the inspection team has enough time to perform every test without rushing.
Statistical Weight
Results from this group of units are used to project the quality level of the thousands of items remaining in the cartons. Accurate measurement of the sample quantity is the only way to validate that the production run meets the requirements of the purchase order.