What Is Quality Inspection? (With Benefits And Types)

Updated 31 July 2023

Quality inspection refers to the preventive measures companies use to detect defects in manufactured products or services before they reach the end user. Manufacturing companies implement a wide array of quality inspection approaches to inspect and test product quality to ensure that the product achieves the desired specifications and customer expectations. Learning about quality inspection can help you avoid inconsistencies and defects in manufacturing. In this article, we answer the question, 'What is quality inspection?', discuss its benefits and types and explain how to create a quality inspection checklist.

What Is Quality Inspection?

Learning the answer to the question, 'What is quality inspection'? can help companies, quality inspectors and other quality assurance employees implement effective inspection protocols to achieve the desired output quality of manufactured products or services. Quality inspection is the formal procedure of measuring, examining and testing one or more product features and comparing the measured results with specified requirements to determine whether the product complies with manufacturing standards. It applies to raw materials, semi-finished goods and finished products. Quality inspectors use checklists to evaluate the product based on pre-defined specifications.

Benefits Of Quality Inspection

Quality inspection offers numerous benefits to both manufacturers and end customers. Here are a few advantages of implementing quality inspection:

Improves production efficiency

Production efficiency occurs when all elements in the production assembly chain function optimally. Businesses can achieve production efficiency with error-free machinery, high-quality materials and competent employees. Quality inspection increases production efficiency by detecting and eliminating manufacturing errors throughout the production cycle, helping manufacturers achieve their production goals quickly.

Enhances cost efficiency

Periodic quality inspections can help companies reduce their manufacturing costs significantly. It helps businesses optimise their production cycle and minimise the use of manufacturing resources by preventing quality issues, defects, repairs, rework and returns. This helps companies reduce cost-related problems, achieving cost-efficiency in the long term.

Shortens product approval cycles

Incorporating product feedback into the manufacturing cycle helps companies improve product approval. The quality inspection process helps in reducing the time to market by eliminating manufacturing defects. Customers and other stakeholders can read inspection reports to track product changes and quality control measures, leading to quicker approval.

Enhances customer trust

Customer trust in a product, brand or company depends on the product quality. Products of high quality with minimal defects increase customer trust and brand loyalty. Conducting quality inspection can improve the quality of the manufactured product. This helps generate a positive customer response, enhancing their confidence in the business.

Encourages business growth

Business growth depends on several factors, including consistent product quality and cost-efficiency. Regular product inspections can help you achieve these factors. Quality inspections also help the manufacturer gain the trust of business partners, customers and other stakeholders, building a positive brand reputation amongst the general public.

Creates a positive work environment

Quality inspections help create a safe work environment as it helps in reducing risky manufacturing practices and other workplace hazards. This provides a positive and safe workplace for all production line employees, allowing them to focus on their work without worrying about potential workplace accidents. A safe working environment also helps retain employees, reducing employee turnover.

Builds brand authority

Quality inspections can help companies establish themselves as trusted industry leaders by eliminating product defects and gaining customer trust. For example, printers can use quality inspection procedures to manufacture products of the highest quality without faults, reducing the risk of expensive reprints or recalls. This helps save customers' time and money and avoids potential damages to reputation. When customers notice that a company takes all precautions to prevent defects and mistakes, they are likely to trust the business, which establishes the company as the brand authority in their niche.

Types Of Quality Inspection

Quality inspection is of several types, based on their role in supply chain management and product quality requirements. Depending on the product and supplier experience, a company might apply one or all of these quality inspection methods. The five major types of quality inspections are:

Pre-production inspection (PPI)

Companies conduct the pre-production inspection before the commencement of the production process. It helps manufacturers assess the quality and quantity of the raw materials and evaluate if they conform to relevant specifications. Businesses generally rely on a PPI when working with new suppliers, especially if the project has critical delivery dates. A pre-production inspection helps to eliminate communication errors between the manufacturer and the supplier regarding quality expectations, shipping dates and delivery timelines. It helps companies reduce any errors or mistakes before production, helping to avoid significant losses during the later production stages.

During production inspection (DPI or DUPRO)

During production, inspection is beneficial for products that are in continuous production and have strict quality requirements. Generally, manufacturers implement a DPI when they notice quality issues during the PPI. Quality inspectors conduct DPI inspections after completing the manufacture of 10% to 15% of units so that they can identify any deviations and defects. DPI helps quality inspectors maintain product quality throughout the production process, as it helps in the early detection and correction of quality issues, reducing rework and delays during the later stages.

Pre-shipment inspections (PSI)

Pre-shipment inspections ensure that the product complies with the buyer's requirements and specifications. It happens before manufacturers ship the completed product to the customer. Quality inspectors conduct the PSI on completed products when the team has finished manufacturing at least 80% of the order. The inspector selects random samples to inspect for defects against the relevant standards and specifications.

Loading supervision (LS)

Also known as container loading and unloading inspection, LS ensures that product handlers load and unload the products correctly onto the shipping containers. Inspectors supervise the whole process to guarantee the safe arrival of the finished product at the final destination. This process happens at the factory, where handlers load the products into the shipping container and at the destination during unloading. LS also evaluates the shipping container's condition, packaging compliance and product quantities.

Piece-by-piece inspections

As the name implies, a piece-by-piece inspection involves checking each item to evaluate various factors like appearance, functionality, craft and safety. Quality inspectors conduct piece-by-piece inspections either before or after the pre-shipment assessment. A piece-by-piece review is mandatory for high-value goods to ensure compliance with specifications. Once this process is over, quality inspectors seal and certify each product with a sticker to ensure that it meets specified quality requirements.

What Is A Quality Inspection Checklist And How Do You Create One?

Quality inspectors use a list to verify the quality of manufactured products. This checklist provides quality inspectors with step-by-step instructions and clear criteria to follow when inspecting products. You can use these tips to create a quality inspection checklist:

Identify potential defects and build a defect list

Different products are prone to varying defects. Begin by analysing the product's characteristics and identify possible defects that might occur. For example, if the company sells electronics, a possible defect is incorrect voltage and a company that manufactures wooden furniture might identify splinters as a potential manufacturing defect. You can use customer complaints and feedback to get a list of defects that have happened in the past.

Once you have a list of potential defects, categorise the list based on defect severity. For example, a wood splinter can cause injury to the end customer, so it is more severe than a minor scratch. You can divide the defect list into three categories based on severity, including critical, major and minor. If you outsource the quality inspection to a third-party inspection service provider, you can collaborate with them to build this list of potential product defects.

Split the checklist into different sections

Depending on the type of product, you can divide the checklist into the following sections:

Packaging and labelling: This section includes items that help the inspector verify if the product packages are in good condition without any physical damage. For example, you can check if the shipping labels are clear and legible with the correct contact details.
Visual inspection: This includes items that help the inspector visually check the product. For example, inspectors can look for missing screws or peeling paint when inspecting pieces of furniture.
Physical requirements: Check if the product matches all physical specifications like weight, size and height. Inspectors use tools like callipers and measuring tape to verify physical requirements.
Functional testing: Here, the quality inspector verifies whether the product works as intended. For example, inspecting a piece of furniture, the inspector checks if the furniture stands firmly without rocking.
Special tests: These depend on the product's unique attributes. For example, if the product requires the customer to assemble it, the inspector might verify if all the parts fit.

What Is Quality Inspection? (With Benefits And Types)