When a during-production inspection is most useful

This article describes common industry practice, not official rules.

A during-production inspection is usually carried out while part of an order is finished and the rest is still being made. That timing lets a problem found in finished units be corrected in the units that are not made yet. The exact timing is agreed between the buyer and the factory and written into the purchase contract or the booking with the inspection company.

When buyers commonly add it

Buyers often add this inspection in some situations. The list below covers cases where it is often chosen, not every order.

• A new supplier that has not made the buyer's product before.
• A new product, or a product where the design, a material or a component has changed.
• A long production run, where a fault made early could repeat across many units.
• A tight shipping date, where a problem found after packing leaves little time to fix.
• Problems found at the pre-production stage, such as a sample that does not match the approved sample, or a material that differs from the specification.
• A product where a fault is costly to fix once packed, for example when rework means the cartons are reopened, the goods are sorted and the cartons are packed again.

What it usually checks

The checks depend on the contract and the inspection instruction. A common set looks like this:

• The first finished units compared with the approved sample and the buyer's specification.
• Workmanship, such as stitching, finishing, labels, assembly and surface quality.
• Measurements taken against the technical drawing, using the points set in the inspection checklist.
• Function tests the buyer has asked for, carried out on site with the factory's own equipment.
• Packing materials, inner packing, and how the cartons are marked against the shipping marks.
• The factory's own in-line records, such as the quality control records kept at the line.

The inspector usually selects units from the finished part of the run. The sampling method and the size of the sample are set in the inspection instruction or the contract, not chosen on the day. Each defect is usually recorded as critical, major or minor, using the classes the buyer defined.

What the buyer can do with the result

A common approach is to read the report next to the approved sample and the specification. The buyer can then decide on the next step. Options commonly include:

• Asking the factory for corrective action while production continues, such as sorting, rework or a change to the line setup, as the contract allows.
• Changing the later inspection, for example by checking a larger sample or adding checks on the part that failed.
• Deciding whether to keep the remaining production going or to hold it until the issue is fixed. This is a commercial decision and it depends on the contract.
• Booking a re-inspection after rework, so the fixed units are checked again.

What it cannot show

This inspection looks at units that already exist at the time of the visit. It cannot show how units not yet made will turn out, or what the factory will do with materials that have not arrived. Units still on the line, or still in storage, are outside what the visit covers.

It also does not replace the final inspection before shipment. A during-production visit and a final random inspection cover different units, so they are often used together.

Laboratory testing is a separate activity. A laboratory measures properties under controlled conditions and issues a test report that describes what was measured and how. A during-production visit does not produce such a report.

Whether a legal or certification requirement applies is for the regulator or an accredited laboratory to confirm.

How to brief the inspector

It helps to send the inspector the approved sample, the specification, the technical drawing, the packing list and the inspection checklist before the visit. It also helps to agree in writing which checks are on the list and what counts as a critical, major or minor defect.

An inspection is usually carried out by a third party that is not the factory or the seller. The report then records what the inspector saw during the visit, which is the point of having one.