What is quality control, and how is it implemented?

Quality control is a preventive approach that helps businesses anticipate potential problems while strengthening their reputation. Far from slowing production or driving up costs, a well-implemented quality control system is closely tied to productivity, enhancing performance. In today’s digital era, quality control is evolving with sensors, AI algorithms and big data, enabling companies to gain deeper insights into every aspect of their operations and supply chains.

In this post, we explore what quality control is, in addition to the different types, its benefits and how it’s applied in logistics.

What is quality control?

Quality control is a set of procedures organisations use to assess the suitability, effectiveness and condition of their products and services. It involves techniques, activities and actions designed to guide processes and eliminate potential deviations. Effective quality control is essential to a business’s overall performance. It increases customer satisfaction, operational efficiency and continuous improvement while reducing long-term costs.

The goal of quality control is to prevent, identify and correct errors or defects — ideally during production, before the product reaches the end customer or enters another manufacturing stage. To achieve this, companies conduct a series of checks, from design-stage lab testing and simulations to pre-production material inspections.

Types of quality control

There are several types of quality control, depending on the approach and evaluation criteria:

• Statistical quality control (SQC). This method collects and analyses data to assess product or service performance. An example of SQC would be sampling production batches and employing statistical indicators to verify whether they meet quality standards.
• Process quality control. Organisations review production and/or service delivery to find improvement opportunities and confirm that each stage meets set standards. This might involve spotting bottlenecks or deviations.
• Product quality control. This method focuses on the end result, ensuring the finished product or service fulfils established criteria.
• External quality control. Independent entities or third parties review processes from an impartial perspective.
• Internal quality control. This type is conducted by employees within the company.

Benefits of quality control

Some quality controls are mandatory, while others are voluntary. Either way, investing in quality control brings multiple advantages:

• Customer loyalty. Satisfied customers are more likely to buy again, boosting brand reputation.
• Lower costs. Quality minimises expenses from errors and returns. Correctly maintained machinery, high-grade raw materials and skilled labour reduce waste and rework.
• Higher profits. Superior quality can justify premium pricing, increase market share and drive operational growth.
• Positive work environment. When employees perform competently, they take pride in their work, improving productivity and morale.
• Greater competitiveness. Quality control ensures products and services meet established standards. This cuts costs linked to errors and returns, strengthening customer trust and reputation.

Who oversees quality control?

Though third-party audits are commonplace, large organisations often have a quality department responsible for inspections. Control duties can also extend to other areas of a business, from management to operators.

The quality department maintains and monitors quality requirements for products and services. Other responsibilities involve coordinating and preparing internal audits and participating in external ones. To that end, the department collaborates with certification authorities and analyses customer feedback. Quality professionals act as a bridge between a company and the external regulations that affect it.

Quality control in logistics

In logistics, quality control covers every link of the supply chain, from goods receipt and storage to distribution. Its purpose is to guarantee that products reach customers in optimal condition and at the right time.

To monitor each logistics stage, organisations can leverage a warehouse management system (WMS). This software is a key tool for anticipating issues, maintaining traceability and preserving product integrity until delivery.

• Receiving: verifying that incoming goods match purchase orders in quantity, condition and specifications. Visual inspections detect damage, and supplier services are also evaluated.
• Storage: ensuring items are correctly slotted, labelled and kept in correct conditions.
• Order picking: selecting the right items in the stipulated quantities, with accurate documentation.
• Packing and shipping: confirming that orders are securely packaged and comply with client and shipping requirements.
• Transport: tracking deliveries to verify that deadlines are met and product conditions are maintained throughout transit.

Quality control tools

In the 1960s, Kaoru Ishikawa, a professor at the University of Tokyo, developed seven analytical tools that became the foundation of quality control. These simple yet effective methods help identify, analyse and solve issues in production, logistics and service processes.

• Pareto chart: pinpoints the main sources of a problem, based on the 80/20 rule — 80% of effects often stem from 20% of causes.
• Scatter plot: analyses the relationship between two variables.
• Ishikawa (fishbone) diagram: categorises the root causes of a problem visually, with the head representing the issue to be resolved and the spine its possible origins.
• Stratification: divides data into subgroups with shared characteristics for more detailed analysis.
• Control chart: monitors processes over time to detect predictable or irregular behaviour.
• Histogram: summarises data distribution to uncover trends or patterns.
• Check sheet: collects and organises information to record results and track trends.

Quality, productivity and customer loyalty

Quality control goes far beyond inspecting products. It’s a preventive and strategic philosophy that involves the entire organisation — from management to shop floor workers — in optimising processes, raising productivity and increasing competitiveness. Rather than an expense, it’s an investment that brings down costs, boosts profits and enhances a company’s reputation.

In logistics, it ensures goods maintain their integrity throughout the supply chain, reaching customers in perfect condition. In today’s digital era, automation and data analytics are transforming quality control, making it more accurate, proactive and efficient than ever before.