Materials that require repeated sampling inspection typically include those with high variability, critical applications, or those that are expensive or difficult to replace. These materials often undergo rigorous quality control measures to ensure consistency and reliability. For instance, in the aerospace industry, materials like titanium alloys and carbon fiber composites are subject to repeated sampling inspection due to their critical role in aircraft performance and safety. According to a report by the Aerospace Industries Association, over 80% of aerospace components undergo some form of sampling inspection to ensure compliance with stringent quality standards. Similarly, in the pharmaceutical industry, active pharmaceutical ingredients (APIs) and drug substances are frequently sampled and inspected to guarantee their purity and efficacy, as per guidelines set by the FDA. This repeated inspection is crucial to prevent defects and ensure that the final product meets the required specifications.