Garment Inspection Procedures in Mexico: AQL and Sampling Methods

Quality inspectors rely on globally recognized frameworks, such as the Acceptable Quality Limit (AQL) and standardized sampling methods, to thoroughly assess garments at various stages of production. Inspections are conducted before, during, and after production to detect defects early and maintain consistency.

Inspection procedures ensure that apparel products meet international quality standards and buyer specifications before reaching the market.

Studies show that nearly 10-15% of apparel shipments face rejection due to quality issues, which highlights the need for strict inspection processes to maintain global standards.

This blog explores garment inspection in Mexico, with a focus on AQL and sampling methods to ensure quality and protect brand reputation.

What Is Garment Inspection?

Garment inspection is the process of examining apparel at different production stages to ensure products meet quality, safety, and buyer specifications. It involves checking stitching, sizing, colour consistency, labelling, and overall finishing using sampling methods and globally recognised standards, such as the Acceptable Quality Limit (AQL). It helps brands prevent costly returns, shipment delays, and customer dissatisfaction while ensuring compliance with international quality standards. For companies sourcing from Mexico, garment inspections are crucial to maintaining product quality and protecting their brand reputation.

Understanding AQL in Garment Inspection?

The Acceptable Quality Limit (AQL) is a globally recognized standard used in garment inspections to determine the maximum number of defective products allowed within a production batch. It helps brands strike a balance between quality and efficiency by inspecting a representative sample rather than checking every single item.

For example, if a brand orders 10,000 t-shirts from a factory in Mexico, inspecting every unit would be costly and time-consuming. Instead, inspectors use AQL tables to select a sample size of 200 pieces and set a defect tolerance limit. If defects within that sample are within the acceptable range, the entire batch passes inspection. If they exceed the limit, the batch fails, and corrective actions are required.

Brands sourcing from Mexico rely on AQL because it standardizes quality expectations between buyers and manufacturers, ensuring smoother collaboration and fewer disputes over defective products.

AQL Levels and Defect Classification for Garment Inspection

In garment inspections, the AQL standard determines the acceptable number of defects based on the product's price, quality, and market positioning, as shown in the table below.

AQL Standards for Garment Inspection in Mexico

Sampling Methods Used in Garment Inspections

After understanding the importance of AQL standards and how defects are classified, the next step in garment quality control is deciding how many pieces to inspect from a production batch. Most garment factories in Mexico follow international sampling standards, such as ISO 2859-1, to ensure a consistent, transparent, and reliable inspection process. It provides a structured framework for selecting representative samples from each production batch and setting clear defect tolerance limits based on AQL (Acceptable Quality Limit) levels.

The following are the widely used sampling methods in garment inspection:

No Sampling Inspection

In this method, no samples are checked during production or before shipment. The entire production batch is accepted without any inspection based on the factory's credibility and past performance.

• Use Case: Applied when working with highly trusted factories or long-term suppliers with a proven quality track record.
• Limitation: Risky for new suppliers, as defects may remain undetected.

100% Inspection

It involves checking every single garment in the production batch to ensure it meets the buyer's specifications.

• Use Case: Used for high-value garments, luxury apparel, or safety-critical clothing where zero defects are acceptable.
• Example: Inspecting medical uniforms, fireproof clothing, or designer gowns before shipment.
• Limitation: Time-consuming and expensive, making it unsuitable for large production runs.

Spot Checking

In this method, inspectors randomly select a few garments from the production lot and check them for quality issues.

• Use Case: Commonly used during quick inspections where time is limited.
• Example: Picking 20 garments from a 1,000-piece t-shirt order to verify stitching, labelling, and finishing.
• Limitation: Since only a few pieces are checked, defects in uninspected items may go unnoticed.

Arbitrary Sampling

Here, inspectors select samples based on their personal judgment rather than statistical methods. It is less structured and usually relies on experience.

• Use Case: Suitable for small production runs or when buyers and inspectors are physically present at the factory.
• Example: An inspector may choose garments from specific bundles that look suspicious or seem inconsistent.
• Limitation: Results are subjective and may not accurately represent overall batch quality.

Acceptance Sampling (AQL Sampling)

It is the most widely used sampling method in the garment industry. Inspectors select a specific number of garments based on AQL (Acceptable Quality Limit) standards and inspect them thoroughly.

• Use Case: Ideal for large-scale garment production where statistical accuracy is needed.
• Example: For a 5,000-piece jeans order, inspectors might test 125 randomly selected garments following ISO 2859-1 guidelines.
• Advantage: Provides statistically reliable results and ensures international quality compliance.

Determining the Right Sample Size

The sample size in garment inspection varies depending on several key factors:

• Batch Size – Larger production lots require more samples to accurately represent overall quality. For example, a 500-piece order may need 50 samples, while a 10,000-piece order may require 200 or more.
• AQL Levels – Stricter AQL standards demand larger sample sizes to detect defects precisely. For instance, a luxury brand using AQL 1.5 might test 300 pieces, while a budget t-shirt order under AQL 4.0 may only test 80 pieces.
• Garment Type & Price – Luxury garments require more detailed inspections, whereas budget items allow smaller samples. For example, a premium dress order may test 20% of the batch, while basic t-shirts may require just 5%.

Step-by-Step Garment Inspection Process in Mexico

Garment factories in Mexico follow a structured inspection process to ensure that every product meets international quality standards and buyer specifications. The process typically involves three key stages: Pre-Production Inspection (PPI), During Production Inspection (DUPRO), and Final Random Inspection (FRI). These stages enable brands to maintain consistent quality, detect issues early, and prevent costly delays or rejections.

Pre-Production Inspection (PPI)

The Pre-Production Inspection is conducted before the start of garment manufacturing. Its main objective is to verify that all raw materials, fabrics, trims, labels, and other components comply with the quality standards and specifications set by the buyer.

• Inspectors verify fabric quality, color consistency, and shrinkage levels.
• Labels, buttons, zippers, and other accessories are checked for accuracy and durability.
• Factories confirm that production samples match the approved designs.

Example: For a 5,000-piece polo shirt order, inspectors test the fabric's GSM, colour fastness, and button durability before bulk production begins, ensuring the final garments meet buyer expectations.

During Production Inspection (DUPRO)

The During Production Inspection is conducted midway through manufacturing, usually when 20% to 60% of the garments have been completed. Its main goal is to identify defects early and ensure the factory maintains consistent quality standards throughout production.

• Inspectors randomly select samples from the ongoing production line.
• They check stitching quality, sizing accuracy, fabric alignment, and colour consistency.
• Any defects are documented, and corrective actions are immediately taken to prevent further issues.

Example: In a 10,000-jeans production run, inspectors test 200 randomly selected pieces to check zipper strength, seam alignment, and measurement accuracy. If defects exceed the acceptable AQL limit, production is paused until corrections are made.

Final Random Inspection (FRI)

The Final Random Inspection is carried out after 100% of production is completed but before shipment. Inspectors select a representative sample using AQL-based sampling methods to confirm the entire batch meets buyer requirements.

• Garments are checked for overall quality, artistry, labelling, packaging, and barcoding accuracy.
• The inspection verifies colour consistency, fabric defects, size accuracy, and finishing quality.
• If the sample passes AQL standards, the shipment is approved; otherwise, corrective measures are required.

Example: For a 20,000-piece order of branded t-shirts, inspectors randomly pick 315 pieces using ISO 2859-1 guidelines. If defects are within the acceptable range, the shipment is cleared for delivery.

Key Challenges in Garment Inspections in Mexico

While Mexico has become a preferred hub for garment manufacturing, maintaining consistent product quality can be challenging. Several factors affect inspection efficiency and reliability:

• Variations in Local Factory Quality Standards: Different factories often follow their own internal quality standards, which may not align with the expectations of international buyers. Without proper monitoring, it can lead to inconsistent product quality across batches.
• Communication Gaps Between Buyers and Manufacturers: Misunderstandings regarding product specifications, AQL levels, and inspection requirements can result in defective shipments or delayed production schedules. These issues are more common when brands and factories operate in different time zones or languages.
• Ensuring Consistency Across Multiple Production Sites: Large orders are often split between different factories to meet tight deadlines. Without centralized quality control, maintaining uniform standards across all facilities becomes challenging, which increases the risk of defects and shipment rejections.

Best Practices for Brands Sourcing from Mexico

To overcome these challenges and ensure high-quality garment production, brands should adopt the following practices:

Partner with Reliable QC Service Providers

Work with experienced quality control companies or on-site inspection teams in Mexico to monitor production at every stage and ensure compliance with international standards.

Establish Clear Product Specifications and AQL Levels

Define detailed product requirements, including measurements, colours, trims, packaging, and acceptable defect limits based on AQL standards, to avoid misunderstandings with manufacturers.

Using tools like Techpacker or WFX PLM can help create clear, visual tech packs for better alignment.

Use Real-Time Digital Inspection Reports for Transparency

Leverage technology-driven quality control tools like Inspectorio Sight, QIMAone, or GoCanvas that provide instant digital reports, photos, and defect data, helping brands track production quality in real-time and make quick, informed decisions.

Leverage Third-Party Inspection Agencies for Unbiased Results

Hiring independent inspection companies ensures an objective assessment of product quality, reducing risks associated with in-house factory bias and providing greater confidence before shipment.

Unlock the essential quality inspection checklist that ensures every garment you source meets rigorous quality standards.

AMREP Mexico: Your Trusted Partner for Garment Quality Control in Mexico

AMREP is a trusted partner for global brands sourcing apparel from Mexico, specializing in garment quality inspections to ensure consistent quality and compliance with international standards. With expertise in AQL-based quality control and end-to-end inspection solutions, AMREP provides complete transparency and confidence throughout the production process.

Partner with AMREP today to streamline your sourcing, protect your brand reputation, and deliver garments that exceed customer expectations.