Visual Inspection

‍Visual Inspection is a quality control technique used to physically examine products, components, or manufacturing materials for visible flaws or deviations from specified standards.

Visual Inspection is a critical, mandated quality control process in which personnel systematically look for nonconformities or physical anomalies, ensuring that products meet predetermined criteria before they are approved for use or distribution.

Visual inspection is often the first line of defense in maintaining product quality, though in modern manufacturing, it must be supplemented by more advanced techniques to guarantee safety.

Visual Inspection in Quality Management Systems (QMS)

Within a robust QMS, inspections such as visual examinations are considered mandatory control procedures under Acceptance Activities (820.80).

Acceptance Criteria: Manufacturers must establish and maintain procedures for inspection, testing, or other verification activities to ensure that incoming, in-process, and finished products conform to specified requirements.

Documentation: All acceptance activities, including visual inspection results, must be thoroughly documented. These records are necessary to maintain compliance and become part of the Device History Record (DHR) for the product.

Controlling Product Flow: The acceptance status (indicating conformance or nonconformance) determined by inspection must be visibly maintained throughout the product’s lifecycle (manufacturing, packaging, labeling, installation, and servicing) to guarantee that only conforming product is distributed, used, or installed.

Specific Example: Inspection of Medical Gloves

For highly regulated products like surgical and patient examination gloves, compliance is determined through a combination of visual examination and functional tests, such as a water leak test.

Procedure: The visual inspection involves carefully removing a glove from the package and examining it for defects.

Defects Identified: These inspections look for apparent integrity failures, including tears, embedded foreign objects, material extrusions, or gloves that are fused together or that adhere and tear when separated. Any visual defect likely to affect the glove's barrier integrity is considered.

Counting Defects: If multiple defects are found in a single glove, they are typically counted as one defect for the required count.

Limitations and Advanced Techniques

While essential, reliance solely on human visual inspection has inherent limitations, especially for complex or critical components:

Human Limits: Traditional visual inspection is generally limited by human capabilities; the human eye may miss minor defects, subtle cracks, or surface irregularities.

Hidden Defects: This traditional approach often fails to detect subtle defects or those hidden beneath surfaces or within enclosed internal structures.

Modern Alternatives: Modern methods, such as Industrial CT scanning, surpass visual inspection by using X-rays and advanced data reconstruction to inspect complex assemblies in situ, providing a comprehensive 3D view of internal structures. This non-destructive scanning enables the detection of defects like minuscule cracks, porosities, and misalignments that are not visible to the naked eye or detectable by many traditional inspection methods.

Analogy for Understanding Visual Inspection

If performing all quality controls on a complex device is like checking all the paperwork and testing the engine of a commercial jet, then Visual Inspection is simply walking around the outside and checking for dents, missing rivets, or visible cracks. It is the necessary, non-technical initial check, but it cannot confirm the integrity of the engine block (which requires methods like advanced CT scanning).

‍