What Is Skip-Lot Inspection?

Skip-lot inspection is a quality control process that reduces inspection effort by testing only selected lots instead of inspecting every lot. It is commonly used when a production process or supplier has demonstrated consistent quality over time. Skip-lot inspection is intended for stable processes with a demonstrated history of acceptable quality. It is generally not recommended for new products, unstable processes, or suppliers with inconsistent quality.

Skip-Lot testing is sometimes referred to as “Frequency Testing” depending on the region and industry.

With skip-lot inspection, every lot is initially inspected. After a defined number of consecutive successful lots, some lots are intentionally skipped according to established rules. If a future inspection fails, the process typically returns to inspecting every lot until confidence in quality is restored.

Example skip-lot patterns could be:

• Inspect every third lot.
• Test 1 then skip every 3rd batch.
• After 20 accepted receipts, inspect every fifth receipt.
• If any receipt fails, return to inspecting every receipt for the next 10 receipts.

Skip-lot inspection helps organizations:

• Reduce inspection time and labor.
• Lower quality control costs.
• Focus inspection resources where they provide the most value.
• Maintain confidence in proven suppliers and stable manufacturing processes.

Common examples include:

• Receiving inspections for trusted suppliers.
• Testing every second, fourth, or tenth lot.
• Reducing inspection frequency after a series of successful inspections.
• Returning to full inspection when defects are detected.

Quality Inspector supports several approaches to implementing skip-lot strategies.

Related Articles

General Skip-Lot Concepts

Skip Lot Inspections in Quality Inspector

Provides an overview of skip-lot inspection concepts and configuration.

https://kb.dmsiworks.com/knowledge-base/skip-lot-inspections-in-quality-inspector/

Skip-Lot with Sampling

Sampling and Skip Lot in Quality Inspector

Explains how skip-lot inspection works together with sampling plans.

https://kb.dmsiworks.com/knowledge-base/sampling-and-skip-lot-in-quality-inspector/

Receiving Inspection Scenarios

Implement Skip Lot with Receiving in Quality Inspector

Shows how to use skip-lot inspection with receiving processes and incoming goods.

https://kb.dmsiworks.com/knowledge-base/implement-skip-lot-with-receiving-in-quality-inspector/

Fixed Frequency Testing

Implement a Test Every X Lots Scenario with Skip Lot in Quality Inspector

Demonstrates how to perform inspections on a defined lot interval, such as every second, fifth, or tenth lot.

https://kb.dmsiworks.com/knowledge-base/implement-a-test-every-x-lots-scenario-with-skip-lot-in-quality-inspector/