Professional Detailing1 min read

Sampling Coating Packs Without Replacement: The Lot Size Matters

When inspected packs are selected without replacement from a finite lot, successive selections are not identical independent draws. The sampling calculation should reflect the actual lot and selection process.

Updated · NANOLAB Knowledge

The key distinction

This matters especially when the sample is a substantial fraction of the lot. A convenient independent-draw approximation should not be applied without checking whether it suits the decision.

Practical checks

  1. Record lot size and sample size.
  2. State whether units can be selected more than once.
  3. Use the approved finite-lot sampling method where required.

Example

Arithmetic example: a hypothetical lot contains ten packs, two defective. Selecting two different packs at random gives a no-defect probability of 8/10 multiplied by 7/9, about 62.2 percent.

Scope and limits

The example assumes perfect inspection and known composition solely to explain the arithmetic. It is not a release plan or evidence about NANOLAB production; actual sampling requires appropriate quality procedures.

Related guidance

Ask NANOLAB about the exact product and intended use. Use the current product documentation for formulation-specific instructions.