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

![Quality Control](https://www.investopedia.com/thmb/LV8P4KOKOzBRa7sCFYYQmdLA2-M=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/Quality-control-d2412c505d014b9d94007cae3dda47f4.jpg)

*— Ryan Oakley / Investopedia*

> **Definition**
>
> Quality control is a process employed by businesses to ensure that their products are manufactured to meet defined quality standards.

## What Is Quality Control (QC)?

Quality control (QC) is a system that ensures that manufactured products are produced and maintained to a high standard. Quality control requires companies to create an environment where management and employees strive for perfection. This is done by training personnel, creating product quality [benchmarks](https://www.investopedia.com/terms/b/benchmark.asp), and testing products for [statistically significant](https://www.investopedia.com/terms/s/statistically_significant.asp) variations.

QC requires the [establishment of well-defined controls](https://www.investopedia.com/terms/a/acceptable-quality-level-aql.asp) to help standardize production and reactions to quality issues.

### Key Takeaways

*   Quality control (QC) not only ensures that a business’s products meet or improve quality standards, but also influences its employees’ attitudes and creates a sense of ownership.
*   QC involves testing units to determine if they are within the specifications for the final product.
*   The quality control used in a business depends on the product or industry, and several techniques exist for measuring quality.
*   The food industry uses quality control methods to ensure customers don’t get sick from their products.
*   Quality control creates safe measures that can be implemented to make sure deficient or damaged products don’t end up with customers.

## Understanding Quality Control (QC)

Creating a product is costly, time-consuming, and can be unsafe without controls in place. A company that puts defective products on the market may be held liable for injuries or issues that arise from using its products. Quality control inspectors ensure that [defective or unsafe products are identified](https://www.investopedia.com/terms/a/acceptance-sampling.asp), and that the causes are corrected.

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

Quality testing is generally completed in each step of a [manufacturing](https://www.investopedia.com/terms/m/manufacturing.asp) or business process. Employees often begin by testing [raw materials](https://www.investopedia.com/terms/r/rawmaterials.asp), pulling samples from the manufacturing line, and testing the finished product. Testing at various manufacturing stages helps identify where a production problem occurs and the remedial steps required to prevent it in the future.

In a nonmanufacturing business, quality testing can involve [customer service](https://www.investopedia.com/terms/c/customer-service.asp) 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.

> **Fast Fact**
>
> 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.

## How Quality Controls Differ by Industry

QC used in a business is highly dependent on the product or [industry](https://www.investopedia.com/terms/i/industry.asp). There may be different processes and regulations that apply. For example:

*   Quality control in food and drug manufacturing includes ensuring the product does not make a consumer sick, so the company performs chemical and microbiological testing of samples from the production or [assembly line](https://www.investopedia.com/terms/a/assembly-line.asp-0).
*   In automobile manufacturing, quality control focuses on parts meeting specifications and tolerances. QC ensures engines, drivetrains, 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](https://www.investopedia.com/terms/s/stresstesting.asp).
*   In aircraft manufacturing, quality control is extremely important. Manufacturers must document, track, inspect, and reinspect all items and phases of a build to build evidence that everything is completed to very strict standards.

## Quality Control vs. Quality Assurance

Quality control and quality assurance (QA) 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, on the other hand, 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 consists of programs and departments that assure upper-level management, customers, and government inspectors that products meet all quality [requirements and safety standards](https://www.investopedia.com/terms/d/declaration-conformity-doc.asp).

## Quality Control Methods

There are several methods quality control uses to communicate and track inspections and issues. For instance, a [quality control chart](https://www.investopedia.com/terms/q/quality-control-chart.asp) 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](https://www.investopedia.com/terms/t/taguchi-method-of-quality-control.asp) is another approach to quality control that emphasizes the roles of [research and development (R&D)](https://www.investopedia.com/terms/r/randd.asp), product design, and product development in reducing the occurrence of defects and failures in products. This 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 that looks at and assesses all product parts. This type of quality control is done to rule out flaws in products. It often evaluates valuable metals and calls for data about the manufacturing process and software to analyze [inventory](https://www.investopedia.com/terms/i/inventory.asp).

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.

> **Important**
>
> 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. Here’s what you may need to become one.

### Requirements

To become a quality control inspector, you’ll need a high school diploma for entry-level positions and higher education for advanced jobs. Many companies prefer candidates with prior work experience in their industry. It also helps if you’re licensed or certified in your field. For instance, the American Society for Quality offers certification for quality control professionals, which can increase your earning potential.

Other qualities needed 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, 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](https://www.investopedia.com/terms/s/six-sigma.asp). 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, or 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. As of May 2024, the U.S. [Bureau of Labor Statistics (BLS)](https://www.investopedia.com/terms/b/bls.asp) reports average salaries as:

*   Professional, scientific, and technical services: $50,300
*   Manufacturing: $48,170
*   Wholesale trade: $46,400
*   Administrative and support services: $37,490

## What Does a Quality Control Inspector Do?

A quality control inspector audits and evaluates a company’s manufacturing and operational processes. They do this by monitoring products throughout the entire production process to ensure they meet the highest standards before they are put on the market. This means reviewing everything from the raw materials used to produce the goods up to the finished products.

## Why Is Quality Control Important?

Quality control ensures that defective goods don’t 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.

## When Does Quality Control Go Wrong?

Quality control can fail for several reasons. It can go wrong when there are no clear standards for production, no protocols in place during the manufacturing process, and a lack of training for employees. Problems also arise when companies don’t address and remedy issues right away.

## The Bottom Line

Quality control helps a business ensure its product quality and overall success. The environment influences employees’ attitudes about the workplace and creates a sense of ownership of the products and company. QC can involve training personnel, creating data-driven tools, testing products, and setting standards.

Quality control methods help create a safe work environment and products that are safe to use and meet customers’ needs. Additionally, QC is a rewarding career for someone who enjoys investigating issues and improving outcomes.

> **Article Sources**
>
> 1.  U.S. Bureau of Labor Statistics. “[Occupational Outlook Handbook: Quality Control Inspectors: How To Become a Quality Control Inspector](https://www.bls.gov/ooh/production/quality-control-inspectors.htm#tab-4).”
>     
> 2.  American Society for Quality. “[Certification](https://www.asq.org/cert).”
>     
> 3.  The Council for Six Sigma Certification. “[Six Sigma Certifications](https://www.sixsigmacouncil.org/six-sigma-certifications/).”
>     
> 4.  American Society for Quality. “[Quality Inspector Certification CQI](https://www.asq.org/cert/quality-inspector).”
>     
> 5.  U.S. Bureau of Labor Statistics. “[Occupational Outlook Handbook: Quality Control Inspectors: Pay](https://www.bls.gov/ooh/production/quality-control-inspectors.htm#tab-5).”