Quality Control: What It Is, How It Works, and QC Careers

Quality Control

Ryan Oakley / Investopedia

What Is Quality Control (QC)?

Quality control (QC) is a process through which a business seeks to ensure that product quality is maintained or improved. Quality control requires the company to create an environment where management and employees strive for perfection. This is done by training personnel, creating benchmarks for product quality, and testing products to check for statistically significant variations.

A significant aspect of quality control is the establishment of well-defined controls. These controls help standardize both production and reactions to quality issues. Limiting room for error by specifying which production activities are to be completed by which personnel reduces the chance that employees will be involved in tasks for which they do not have adequate training.

Key Takeaways

  • Quality control (QC) is a process through which a business seeks to ensure that product quality is maintained or improved.
  • Quality control involves testing units and determining if they are within the specifications for the final product.
  • The quality control used in a business is highly dependent on the product or industry, and several techniques exist for measuring quality.
  • The food industry uses quality control methods to ensure customers do not get sick from their products.
  • Quality control creates safe measures that can be implemented to make sure deficient or damaged products do not end up with customers.

Quality Control

Understanding Quality Control (QC)

Quality control involves testing units and determining if they are within the specifications for the final product. The purpose of the testing is to determine any needs for corrective actions in the manufacturing process. Good quality control helps companies meet consumer demands for better products.

Why Is QC Needed?

Creating a product is costly, time-consuming, and can be unsafe without controls in place. Additionally, if a company sends defective products out for purchase, it could be held liable for injuries or issues that arise from using its products. Quality control inspectors ensure that defective or unsafe products are identified, and the causes are corrected.

How Is It Done?

Quality testing is generally completed in each step of a manufacturing or business process. Employees often begin by testing raw materials, pulling samples from the manufacturing line, and testing the finished product. Testing at the various stages of manufacturing helps identify where a production problem is occurring and the remedial steps it requires to prevent it in the future.

In a non-manufacturing business, quality testing can involve customer service evaluations, questionnaires, surveys, inspections, or audits. A business can use any process or method to verify that its end product or service meets the customer's needs and is safe and legal.

QC Is Different by Industry

The quality control used in a business is highly dependent on the product or industry. For example, in food and drug manufacturing, quality control includes ensuring the product does not make a consumer sick, so the company performs chemical and microbiological testing of samples from the production line.

In aircraft manufacturing, quality control and assurance is of the utmost importance. Manufacturers are required to document, track, and inspect, and reinspect all items and phases of a build to build evidence that everything is completed to very strict standards.

In automobile manufacturing, quality control focuses on parts meeting specifications and tolerances. QC ensures engines, drive trains, and other mechanical parts operate smoothly, efficiently, safely, and as designed.

In electronics, quality testing might involve using meters that measure the flow of electricity and stress testing.

Quality Control vs. Quality Assurance

Quality control and quality assurance are terms often used to define the same thing, but there are distinct differences. Quality control focuses on quality requirements, such as ensuring a part meets specifications. Quality assurance refers to the sum of all actions and processes needed to demonstrate that quality requirements are fulfilled.

What this difference means for quality professionals is that as you move through a quality control career, you might transition from quality control to quality assurance. Quality control is part of quality assurance, which are programs and departments that assure upper-level management, customers, and government inspectors that products meet all quality requirements and safety standards.

Types of Quality Control Methods

There are several methods quality control uses to communicate and track inspections and issues. For instance, a quality control chart is a graphic that depicts whether sampled products or processes are meeting their intended specifications—and, if not, the degree by which they vary from those specifications.

When one chart analyzes a specific product attribute, it is called a univariate chart. A chart that measures variances in several product attributes is called a multivariate chart. Tracking variances allows businesses to see how many defects per production unit they produce and what types of defects are occurring. Here are a few examples of some methods used.

X-Bar Chart

Randomly selected products are tested for the given attributes the chart is tracking. A common form of a quality control chart is the X-Bar Chart, where the y-axis on the graph tracks the degree to which the variance of the tested attribute is acceptable. The x-axis tracks the samples tested. Analyzing the variance pattern on this chart helps you determine if defects are occurring randomly or systematically.

Taguchi Method

The Taguchi Method of quality control is another approach that emphasizes the roles of research and development, product design, and product development in reducing the occurrence of defects and failures in products. The Taguchi Method considers design more important than the manufacturing process in quality control and tries to eliminate variances in production before they can occur.

100% Inspection Method

This 100% inspection method is a quality control process involving looking at and assessing all product parts. This type of quality control is done to rule out flaws in products. This method is often used to evaluate valuable metals and produce. The 100% inspection method calls for data about the manufacturing process and software to analyze inventory.

The challenge of using this method is that looking at every single item used to build a product is expensive and could destabilize or render the product unusable. For example, if you use this method to examine organic strawberries, you risk damaging the berries, rendering them unsellable.

Quality control methods help standardize production and reactions to quality issues in various industries, from food production to automobile manufacturing.

Quality Control Careers

Quality control can be a rewarding career if you enjoy working with people, communicating, presenting results, and working to make products better and safer. To become a quality control inspector, you'll need (depending on the industry):

  • A high school diploma for entry-level positions
  • A bachelor's degree, depending on the industry
  • Experience in an industry
  • Licenses and certifications for some industries and businesses

Other qualities that are necessary for quality control professionals are:

  • Attention to detail
  • Mechanical and math skills
  • Physical abilities and strength
  • Technical skills
  • Performance under pressure

Career Path

The route to a career in quality control and assurance varies by industry, so there may be differences. However, you'll generally need several years of experience in your industry. Typically, you begin by being hired as a quality assurance or control associate after meeting educational and work experience requirements.

Once you gain work experience as a quality specialist or associate, you may move into a senior specialist position and begin managing teams of quality control specialists. You may attend professional development courses sponsored by your employer or be required to gain certifications such as Six Sigma. You might also need to earn a professional designation such as Certified Quality Inspector.

Moving up the career path, you have more options. You may be able to choose from or be selected to be a:

  • QA Systems Manager
  • QA Operations Manager
  • QA Compliance Manager

These positions can lead up to upper-level management or executive levels within quality control:

  • Director of Quality
  • Head of Compliance
  • Vice President of Quality

Quality Control Salaries

The average pay for quality control professionals differs by industry, experience, and position. Pay increases as you gain more experience and move into management positions. The Bureau of Labor Statistics reports average salaries as:

  • Professional, scientific and technical services: $46,280
  • Manufacturing: $40,020
  • Wholesale trade: $37,800
  • Administrative and support services: $30,070

What Does Quality Control Mean?

Quality control means how a company measures product quality and improves it if need be. Quality control can be done in many ways, from testing products, reviewing manufacturing processes, and creating benchmarks. This is all done to monitor significant variations in a product.

What Are the 4 Types of Quality Control?

There are several methods of quality control. These include an x-bar chart, Six Sigma, 100% inspection mode, and the Taguchi Method.

Why Is Quality Control Important?

Quality control ensures that defective goods do not go out to the public. Companies that have quality control methods in place often have employees who pay close attention to their work.

In food and drug manufacturing, quality control prevents products that make customers sick, and in manufacturing, quality control can ensure that accidents don't happen when people use a product.

What Are 3 Examples of Quality Control?

Three examples of quality control could be in the food industry; overseeing the ingredient specifications, reviewing supplier lists, and ensuring the facility where the food product is made is sanitary.

The Bottom Line

Having quality control in place within a business helps ensure product quality and the overall success of a business. The quality control environment influences employees' attitudes about the workplace and creates a sense of ownership of the products and company.

Quality control can be done in various ways, from training personnel to creating data-driven tools to test products and set standards. Quality control methods help create a safe work environment and products that are safe to use and meet customers' needs. Additionally, it is a rewarding career for someone that enjoys investigating issues and improving outcomes.

Article Sources
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  1. American Society for Quality. "Quality Control and Quality Assurance."

  2. Bureau of Labor Statistics. "How to Become a Quality Control Inspector."

  3. ProClinical Staffing. "Quality Assurance Career Path."

  4. American Society for Quality. "Quality Inspector Certification CQI."

  5. U.S. Bureau of Labor Statistics. "Quality Control Inspectors | Pay."