During Production Inspection

During production inspection services from Tetra Inspection give you early visibility into manufacturing quality before defects multiply across your entire order. Our during production inspection (DPI) is an on-site quality control check performed at the 20–60% production stage, allowing you to catch specification deviations, workmanship issues, and material problems while corrections are still cost-effective. As a third-party inspection provider trusted by 2,000+ clients across 45+ countries, we schedule during production inspections within 48 hours across all major sourcing regions in Asia and beyond.

What Is a During Production Inspection?

A during production inspection (DPI) — also called a during production check or in-process inspection — is a proactive quality control measure performed when 20–60% of your order has been manufactured. Unlike a pre-shipment inspection (PSI) that evaluates finished goods at the end of the production cycle, a during production inspection gives you visibility into the manufacturing process itself — enabling early detection and correction of defects before they multiply across the full production run.

The core principle behind a DPI is simple: finding and fixing a problem when 30% of your order is produced costs far less than discovering the same problem when 100% is finished and packed. At the DPI stage, the factory can adjust machinery settings, replace defective materials, retrain workers, or modify processes without having to rework the entire batch. This makes the during production inspection one of the highest-ROI quality control services available to importers.

When Is a During Production Inspection Needed?

A during production inspection is recommended in several key scenarios where the risk of quality failure is elevated:

• First-time suppliers — When you are working with a factory for the first time, you have no track record to rely on. A DPI gives you early insight into whether the supplier can actually deliver to your quality standards.
• Large orders — The larger the production run, the greater the financial exposure if defects are found late. A DPI on a 10,000-unit order can prevent the rework of thousands of units.
• Complex or custom products — Products with tight tolerances, multiple components, custom colors, or intricate assembly sequences are more prone to production drift. A mid-production check catches drift before it becomes systemic.
• Previous quality issues — If prior orders from the same supplier had quality problems, a DPI verifies that corrective actions have been implemented and are being followed consistently.
• Seasonal or deadline-critical orders — When there is no time to re-produce if the pre-shipment inspection fails, a DPI provides an early warning that allows course correction within the original timeline.
• Multi-stage production — Products that go through several manufacturing stages (molding, assembly, finishing, packaging) benefit from inspection between stages to catch issues before they are locked in.

What Does a During Production Inspection Cover?

Our inspectors evaluate multiple aspects of the production during a DPI visit. Each area provides critical information about whether the final product will meet your requirements:

Raw Material and Component Verification

The inspector examines the raw materials and components currently being used in production. They verify that fabric types, metal grades, plastic resins, electronic components, and other materials match your purchase order specifications. Material substitution — where a factory switches to cheaper alternatives without authorization — is one of the most common quality issues in overseas manufacturing, and a DPI is the earliest point at which it can be detected. This is the same category of risk that IQC inspection (incoming quality control) targets even earlier, at the materials-receiving stage.

Work-in-Progress Assessment

Items currently on the production line are examined for process quality. For garments, this means checking stitching quality, seam alignment, and pattern matching. For electronics, it includes solder joint quality, component placement, and wiring integrity. For furniture, the inspector evaluates joint construction, surface finishing stages, and assembly accuracy. Work-in-progress checks reveal systemic issues that will affect every unit still being produced.

Finished Unit Sampling

From the units already completed, the inspector selects random samples for detailed examination. Each sample is compared against your approved golden sample and product specification sheet, with checks for visual quality, dimensional accuracy, color consistency, functional performance, and labeling correctness. Defects are classified as critical, major, or minor and documented with photographs. AQL-based sampling may be applied to the completed portion of the order to provide a statistical quality indicator.

Production Pace and Delivery Timeline

The inspector assesses the factory's production speed, workforce allocation, equipment utilization, and remaining workload to estimate whether the delivery deadline will be met. This is particularly valuable for importers managing tight shipping schedules or coordinating multiple orders. If the factory is behind schedule, you gain advance warning to adjust your logistics planning or push the supplier for acceleration measures.

Packaging Material Readiness

The inspector verifies that packaging materials — inner packaging, retail boxes, carton markings, labels, and barcodes — are available, correct, and ready for use when production reaches the packing stage. Catching a labeling error or incorrect barcode at the DPI stage prevents a failed pre-shipment inspection weeks later.

The Advantage of Catching Defects Early

The economics of quality control strongly favor early detection. Consider the cost trajectory of a defect through the production lifecycle:

• At 20–30% production — Correcting the issue may involve adjusting a machine setting, replacing a batch of materials, or retraining a handful of workers. Cost impact: minimal. Only the affected units need rework.
• At 80–100% production (PSI stage) — The defect has been replicated across thousands of units. Rework requires sorting the entire lot, fixing or replacing defective units, and re-packing. Cost impact: significant. The factory may resist rework on such a large scale, leading to negotiations and delays.
• After shipment — The defect reaches your warehouse or your customers. Cost impact: severe. Returns, refunds, marketplace penalties, customs holds, brand reputation damage, and potential product liability claims.

A during production inspection shifts your quality control from reactive (discovering problems after the fact) to proactive (preventing problems from scaling). For every dollar spent on a DPI, importers typically save many times that amount in avoided rework, returns, and reputational costs.

DPI vs. PSI: Understanding the Difference

During production inspection and pre-shipment inspection are complementary services, not alternatives. Here is how they differ and when each is most valuable:

A DPI is conducted at the 20–60% production stage and focuses on both the production process and the completed units. It answers the question: "Is the factory producing my order correctly?" A PSI is conducted when 80–100% of production is complete and export-packed, focusing exclusively on finished goods. It answers the question: "Are the finished products acceptable for shipment?"

The DPI gives you the power to intervene and correct course during production. The PSI gives you a final quality verdict before you authorize shipment. For high-risk orders, using both provides layered protection: the DPI catches problems early while corrections are affordable, and the PSI confirms that corrections were effective and the full batch meets your standards.

For lower-risk scenarios — established suppliers with a strong quality track record, simple products, or small order quantities — a PSI alone may provide sufficient assurance. But for any order where the cost of failure is high, a DPI is one of the smartest investments an importer can make. Many experienced importers treat the DPI as a non-negotiable part of their quality control program, scheduling it routinely alongside the PSI for every production run. The modest additional cost of a DPI is consistently justified by the defects it catches and the rework costs it prevents.

Real Scenarios Where DPI Saved Orders

During production inspections have saved importers from costly quality failures countless times. Here are scenarios that illustrate the value of mid-production quality control:

A European home goods importer ordered 5,000 ceramic mugs from a new supplier in China. The DPI at 40% production revealed that the factory had switched to a thinner clay body than specified, resulting in mugs that were noticeably lighter and more fragile than the approved sample. The supplier was required to switch back to the correct material for the remaining 60% of production and rework the affected units — a correction that would have been far more expensive and contentious after full production.

An electronics brand sourcing Bluetooth speakers from Vietnam scheduled a DPI at 35% completion. The inspector found that the speaker grille color on production units was visibly different from the approved golden sample due to a pigment batch variation. The factory adjusted the pigment formula for subsequent units and reprinted the affected grilles — avoiding a full-lot rejection at the PSI stage that would have delayed the product launch by three weeks.

A furniture importer discovered during a DPI that the factory had changed the screw type used in shelf assembly, substituting a shorter, lower-grade fastener. The substitution would have caused structural weakness over time. The DPI finding allowed the importer to require the correct fasteners for the remaining production and reinspect the already-assembled units.

A US-based Amazon FBA seller sourcing kitchen gadgets from India scheduled a DPI at 45% production completion. The inspector found that the product labeling did not include the required California Proposition 65 warning, and that the retail packaging dimensions exceeded Amazon's FBA prep guidelines by 2 cm on one side. Both issues were corrected for the remaining production and the affected units were relabeled and repackaged before the PSI — avoiding FBA receiving rejections and potential listing suspension. Without the DPI, these problems would have been discovered only at the pre-shipment inspection or, worse, at the Amazon fulfillment center.

How to Get the Most from Your DPI

To maximize the value of your during production inspection, follow these best practices:

• Provide detailed specifications — The more precise your product spec, the more effectively the inspector can evaluate production. Include dimensional tolerances, color references (Pantone codes), material grades, and functional requirements. Our quality control checklist walks through every checkpoint to define before the inspection.
• Share previous inspection findings — If you have had quality issues with this supplier or product before, share the previous inspection reports with us. Our inspector will pay special attention to the areas that failed previously.
• Time the DPI correctly — Schedule when 30–50% of production is complete for the best balance between having enough units to evaluate and having enough time to correct issues. Scheduling at exactly 20% may not provide enough finished samples; scheduling at 60% limits the correction window.
• Request a timeline assessment — Ask for production pace evaluation as part of your DPI. Knowing whether your supplier is on track to meet the shipping deadline is just as important as knowing the product quality.
• Plan for the PSI — Use DPI results to set your PSI strategy. If the DPI is clean, a standard PSI may suffice. If the DPI reveals issues, consider tightened AQL levels or additional checks at the PSI stage.

Industries Where DPI Provides the Greatest Value

While any manufactured product can benefit from a during production inspection, certain industries see particularly high returns:

• Consumer Electronics — Circuit board assembly, soldering quality, and component accuracy must be monitored continuously during production to prevent batch-wide functional failures.
• Textiles and Garments — Fabric lot variations, dye consistency, sizing accuracy, and stitching quality frequently drift during long production runs.
• Furniture — Wood grain matching, finish consistency, hardware quality, and structural assembly need early verification to avoid costly rework on bulky items.
• Toys and Children's Products — Safety-critical products require early verification of material compliance with CPSIA, EN 71, and ASTM F963 standards.

Scheduling and Coverage

Tetra Inspection schedules during production inspections within 48 hours of booking across China, Vietnam, India, Bangladesh, Turkey, and 30+ manufacturing countries. Reports are delivered within 24 hours, complete with photographs, defect classifications, and actionable recommendations.

For the most comprehensive quality control program, combine your DPI with an initial production check (IPC) at the start of manufacturing, a pre-shipment inspection (PSI) at the end, and a container loading check (CLC) before shipping. If you are evaluating a new supplier, a factory audit before placing your order provides baseline assurance of their manufacturing capabilities and quality systems.

AQL Resources: During production inspections often use AQL-based sampling on completed units to assess quality trends early. To understand how AQL sampling works and how to set the right defect thresholds, explore our complete AQL guide, try our free AQL calculator, or read our guide on how to read AQL charts and sampling tables.