Inspection Methods to Fulfill Quality
Inspection is the act of checking whether a product or service meets its requirements. It has an important role in quality, but Total Quality Management changes how it is used: less reliance on inspecting defects out at the end, and more on building quality in and catching problems at their source.
Questions you may have include:
- What is inspection for?
- What types of inspection are there?
- Why is inspection alone not enough?
The purpose of inspection
Inspection compares an item against a standard to decide whether it is acceptable. It detects problems — but detecting a defect does not, by itself, create quality or prevent the next one.
Types of inspection
- Incoming inspection checks materials and parts received from suppliers.
- In-process inspection checks work as it moves through production, so problems are caught early.
- Final inspection checks the finished product before it reaches the customer.
Inspection may cover every item (100 percent) or a representative sample, depending on cost and risk.
Why inspection alone falls short
Relying on mass final inspection is expensive and imperfect — inspectors miss defects, and the defects have already been made. Deming urged organizations to “cease dependence on mass inspection” and instead build quality into the process. Source inspection, which checks at the point where errors arise rather than at the end, fits this approach by catching mistakes before they become defects.
Summary
Inspection verifies that products meet requirements, using incoming, in-process, and final checks on either every item or a sample. But inspection only detects problems; TQM reduces dependence on end-of-line inspection and emphasizes building quality into the process and catching errors at the source.