Quality Control Methods | 5 mins read

Quality Control Methods- 2 Approaches for Businesses

quality control methods 2 approaches for businesses
Hanh Truong

By Hanh Truong

Quality control methods are strategic procedures that ensure the maintenance or improvement of a product's quality. Generally, these processes include training employees, creating measurable standards for output quality, and periodically testing items to detect any inconsistencies.

With quality management, businesses will enhance the visibility of issues within their manufacturing practices, allowing for corrective actions to be made. Quality testing also guarantees that end products fulfill all production requirements so that consumer expectations can be met.

Strategies for thorough quality assurance are implemented throughout various industries, ranging from automobile manufacturing to food production. While procedures will vary depending on what item is being created and sold, there are 2 main approaches that all businesses must consider for their management systems - inspection and statistical quality control.

2 Common Methods of Quality Control

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Various elements of production - including machinery, materials, and methodology - must be systematically evaluated and controlled to create goods that meet standards of quality.


Inspection is a predominant quality control process and it requires organizations to perform visual and testing examinations on the output and manufacturing processes. This evaluation occurs throughout each step of production - from input, transformation, to output. The 3 important aspects of quality assurance inspections include-

1. Product Inspection

Organizations must assess an item's quality and isolate defective products to prevent them from being sold.

For efficient quality control, inspections should occur regularly. When and how frequently these tests should be done is determined by the company's budgets. However, it is important to keep in mind that skipping the inspection stage altogether will lead to loss of resources due to flawed outputs.

Depending on the circumstances and how many items of a unit are being checked, there are 2 general types of inspections to choose from-

  • 100% Inspection

This quality control process involves thoroughly assessing all items of a product. Using this type of product quality control will make sure there is more accuracy and will eliminate any chance of selling flawed products.

The 100% inspection method is typically implemented to evaluate valuable goods, like gold and silver, or when items are prone to becoming faulty during production processes, like meats and produce.

When conducting 100% inspections, it is necessary to have data about the manufacturing process on hand. Using inventory analysis software would make this easier because users can keep track of wasted items and manage their inventory of finished goods.

However, this method to control quality assurance can be difficult for manufacturers because examining every single item can be costly and can cause some products to be unusable. For example, all bakery goods cannot be inspected because it can lead to broken and unmarketable food items.

  • Sample Inspection

Sample inspection, or partial inspection, uses only a select quantity of a product for evaluation and its results will lead to either accepting or rejecting the entire unit. If a sample is deemed poor quality, businesses may conduct a 100% inspection of the entire stock to confirm the original report.

This process saves money and time for organizations. It also promotes actively monitoring goods at different stages of manufacturing because it can be done quickly.

2. Process Inspection

Process inspection assesses the total quality of raw materials, equipment, and machinery that is used during production. These elements contribute to the creation of a final product and thoroughly inspecting them will ensure high-quality outputs. Process quality inspection minimizes process bottlenecks and reduces wasted resources.

3. Inspection Analysis

Once all inspections are completed, organizations can analyze the information and locate the source of defective products. Using data from inspections, management teams can further understand their production process and assess any necessary changes for quality improvement. They can also confirm that their products meet specifications and calculate extra costs to repair defective products.

An efficient way to streamline analysis is to use a web-based inventory management system because it will provide reports with key insights about spending and waste. This allows organizations to make informed decisions on whether to change raw materials, purchase new machinery, or continue with their business plans.

Statistical Quality Control

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Statistical quality control utilizes statistical measures, such as sampling and probability to uphold quality standards. Industries responsible for mass production or continuous processes commonly use statistical deduction as a tool for quality assurance.

This method can be split into 3 parts-

1. Acceptance Sampling and Analysis

For this approach, a unit of final products must be sampled based on its defining traits and functions. Using acceptance sampling, the batch is tested to determine if it fits standard quality and specifications.

Some defective items can be tolerated and sold in the market, depending on a company's established standards. Acceptance sampling clarifies the degree of marketability and guarantees that only a certain percentage of faulty products are accepted.

To maximize productivity, more samples can be analyzed and the sample size can be increased to represent more products.

2. Process Control and Control Charts

Process sampling should be conducted in tandem with a control chart, which are graphs that indicate changes in manufacturing. This is a common tool for statistical process control because it can identify the tolerable limits of variations in products.

Due to the difficulty of correcting issues caused by probability, differences in quality are acceptable only if it is contained between the range of upper quality and lower quality levels. A control chart can also be used for variations caused by humans or machines and can aid with sourcing the issue. To create a control chart, businesses can follow 3 simple steps.

  • Extract a sample from the unit of goods and measure the characteristics that define its quality, such as weight.
  • Calculate the mean of the measurements and quantify the range of dispersion.
  • With this data, graph, and plot the corresponding numbers.

3. Corrective Measures

The metrics gathered from these statistical methods will increase the visibility of the problems within operational processes. Quality tools, like control charts, will help managers to identify product deviations that occur beyond tolerable limits, to which they can then further investigate and take corrective action.

Benefits of Quality Control

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  • Gain Customers - A study found that 53% of consumers consider quality as the most important factor when purchasing products. Therefore, more people will be attracted to a brand that is reputable for selling goods that have exceptional quality.
  • Ensure Product Safety - Total quality management guarantees that products are safe to use or consume. Organizations will have fewer liability risks, knowing that their items and production process are up to standards and thoroughly monitored.
  • Increase in Customer Loyalty - Customers are more likely to be satisfied with their items and become loyal to the brand if the company is dependable in providing high-quality products that meet their expectations.
  • Positive Branding - Companies that implement quality standards into their business management system will elevate their brand and be known as a reliable source for goods.

By following these two approaches to quality assurance, businesses can optimize their operations and maximize their business' potential in the market.