Quality Control

Quality Control

Customer retention is a point of pride for most companies around the world. Companies spend copious amounts of their budget on marketing geared towards previous customers in hopes they return. They create loyalty programs, frequent buyer privileges, incentives like free shipping for return customers, etc. The reason for all of this is to keep customers coming back, and despite their efforts, these strategies aren’t always successful. Why is it so hard to pinpoint the key qualities that entice customers back? For most consumers, the reason for returning is simple: quality control and quality assurance.

Having strong QA/QC practices is one of the best ways an organization can ensure customer satisfaction. When customers, suppliers, and partners know a company produces high quality work, then they’ll always come back. But being consistent with quality isn’t always easy. Luckily for you, the ins and outs of quality control is what this article will be discussing.

What is Quality Control?

Quality control, or QC, is defined as the testing and inspections performed on various stages of a product’s creation. This practice, often having its own department in a business, allows employees to catch defects and other manufacturing problems before they reach the customer. Quality control is not limited to the manufacturing or food industry either. It can in fact be used in businesses that provide services to customers instead of a physical product. That type of quality control focuses on the employee’s training and overall skill.

Being able to say with confidence that your company produces high quality product depends on a number of factors including machine conditions, training, consistent employees, etc. Those can be incredibly hard to predict, and control, without the right tools. By implementing a stricter quality control process, the user is able to put procedures into place that manage these factors; therefore, enabling the quality to remain consistently high.

The following is an example of the catastrophic consequences that result from a poorly managed quality control standard:

In 2015, Blue Bell, America’s third-largest ice cream manufacturer, was forced to halt production from April to August. They also pulled products from 23 states, including their home state of Texas. To have a recall that huge is devastating at any time, but for an ice cream company, having to recall products for nearly the entire summer was just about the worst scenario imaginable. Fans of Blue Bell bemoaned the recall on social media. Even Texas’ Senator Cruz posed for a photo with a sign that read “God bless Blue Bell.” All of this attention undercut the serious, and entirely avoidable, reason for why this recall and halt in production took place: Blue Bell was found responsible for 10 infections of the bacteria called listeria, three of which were fatal. The worst part? Blue Bell had detected listeria in one of its facilities two years earlier. An investigation later revealed that the outbreak actually dated back to 2010.

Strong quality control measures, as well as quick responses to defects, could’ve prevented Blue Bell’s 2015 recall and, more importantly, saved lives. Implementing a QC program is not that easy, but the benefits outweigh any negatives. A successful quality control program will improve customer retention in the long run, which improves the business’ reputation, and the employees will become inspired to strive for perfection in the work they do.

Arriving to that point of perfection involves putting in the effort to control, manage, and maintain quality. Quality control accomplishes product improvement with a three-fold approach:

  • Implementing controls such as job management processes, performance criteria, and record tracking standards.
  • Prioritizing employee knowledge through training and hiring.
  • Shaping company culture so that values like integrity, team spirit, and continuous improvement are guiding principles for all employees.

How exactly do companies approach those three guidelines for QC? There are many methods for improving quality control in industrial environments. The most common methods begin with:

  • Eliminating Errors – Strong quality control practices like Six Sigma not only help spot quality issues but also work to prevent defects from happening in the first place.
  • Sustained Quality – Quality control practices help detect the root cause of a defect, then revise processes to fix issues and improve overall quality to avoid defects in the future.
  • Improved Compliance – Improving quality control often includes focusing on quality standards, including those that OSHA and other regulatory bodies use to monitor companies and products. 

Applying quality control measures to a facility is a multi-faceted effort that must be put forth by both the employers in the protocols they create as well as the employees who spot quality issues. With that being said, the following sections are the more nuanced details that go into a successful QC program.  

Quality Assurance vs. Quality Control

Quality control and quality assurance are often used interchangeably, when in fact they are two different components to a complete quality management system. The relationship between the two concepts are linked only in that they have the same goal, to meet the company’s quality standards with maximum efficiency. QA/QC are defined as the following:

  • Quality assurance is the confidence that a process will achieve the company’s quality requirements. Think of QA as ensuring the process’ steps are working as they should to create an acceptable final product. QA usually involves product development, design, production, servicing, materials, etc. Consider hiring a quality analyst who is responsible for developing and putting plans into place that ensures all company objectives are met and exceeded.
  • Quality control is the part of quality management that focuses on fulfilling those quality standards put forth by the company. Think of QC as achieving perfection in the end product. The end product is the only thing QC is concerned with.

4 Types of Quality Control

There are four types of quality control that work to eliminate waste such as time and excessive costs, whether that be from defective products or the labor that went into them. These quality control measures include:

  1. Training – Building a team that has the skills to perform tasks efficiently, effectively, and perfectly is an excellent way to ensure customers are getting the quality product they want and deserve.
  2. Adhering to Systems, Processes, and Policies – Creating these three workplace standards are essential for quality control. It’s just like making a recipe; to do it exactly the same as last time, you must follow the instructions given to you that allow for that outcome. The same applies to an industrial setting, employees need instructions to strive for perfection.
  3. Perfect Practice Makes Perfect Product – Refining and practicing those system processes gets the business closer to its goal of consistent quality.
  4. Perform Quality Control Inspections – Quality inspections performed by quality control inspectors, while important to perform for customer satisfaction, is quite the lag indicator. Depending on when the inspection was performed in the production process, the work has been completed and the money has been spent. Use the above three strategies to ensure quality and use final product inspections as a last resort in problem solving.

Supporting the business plan of the company by applying these quality control management techniques to the existing systems, processes, rituals, and routines will help them deliver on the promises they made to their customers.

ISO 9001: Quality Management Systems

Created by the International Organization for Standardization, ISO 9001 is an international standard concerned with quality management and the assurance that companies are effectively documenting quality control to maintain efficient quality management systems. Since ISO is a trusted standards organization throughout the world, holding an ISO 9001 certification means that customers, suppliers, and potential partners can be sure a company meets regulatory requirements and strives toward continuous improvement.

Adhering to the ISO 9001 standard isn’t just for large companies. Even if there are only five employees, this standard helps the business organize their current process, improve the efficiencies of that process, and work to continually improve upon it.

ISO 9001 is based upon a PDCA cycle to give the users the ability to assess the structure, responsibilities and procedures needed to reach an effective QMS. The standard itself contains information on:

  • QMS requirements.
  • Management responsibilities.
  • The appropriate management of resources.
  • The necessary steps needed from the design stage to the final delivery.
  • The use of internal audits and both corrective and preventative action discovered though the intentional measurement, analysis, and need for improvement within a QMS.

There are seven principles of ISO 9001 for business owners to take into account as a certified entity:

  1. Leadership
  2. The Engagement of Everyone
  3. Process Approach
  4. Improvement
  5. Evidence-Based Decision Making
  6. Relationship Management
  7. Customer Focus

To get more of an idea of what kind of work goes into this kind of certification and subsequent actions that those who hold an ISO 9001 certification must take to maintain it, take a look at this cookie business example here.

Statistical Process Control

An important part of quality control and quality assurance is being able to find and monitor problems, collect data, and model systems within the production process. Being able to participate in these types of activities is critical to understanding what is going wrong. That in turn enables employees to then find solutions to problems. This is the job of statistical process control.

Statistical process control, used in a real-time software or program, applies statistics to directly control a production method’s “inputs.” By setting control limits, the data is gathered and placed on a graph. It is incredibly important to differentiate between random variation and nonrandom variation in a production process because it allows the users to figure out where the problem lies. That information can be gathered from the control chart graph. Data that falls within the control limits is more often than not a natural variation, whereas data that falls outside of those limits indicates an issue that needs to be resolved before defective product is created.

By using statistical process control in real time, the business will benefit from:

  • Reduced variability
  • Improve productivity
  • Reduce costs
  • The ability to recognize hidden process deviations
  • Have the ability to immediately act upon process changes
  • Make good decisions in real-time

How Does Mass Production Affect Quality Control?

Mass production often results in lower manufacturing costs, which in turn lower the price for consumers—another aspect of customer retention that is coveted by businesses. However, mass production also calls for a higher level of attention to detail, and most importantly, predicting future problems before they occur.

How does quality control relate to mass production? Well, predicting problems before they occur in production is a big part of quality control and quality assurance systems. Especially when a high volume of product is being produced. Think about it. If something goes amiss and hundreds of defective products are created before anyone notices, then the company has wasted money on products that won’t be able to be sold to customers.

To achieve this, try using total quality management techniques, also known as TQM. While it is similar to Six Sigma in that they both reduce the number of defects in production, TQM primarily focuses on the business’ internal guidelines and specific process standards to reduce errors within production. Using TQM is an ongoing process that streamlines the supply chain, improves customer service, and ensures employees are trained for the job. Using TQM not only helps meet quality standards set by the company, but it also helps work to improve them further.

Quality Control Tools

As can be seem from the sections above, there is no one sure route to a successful quality management system. In fact, there are quite a lot of tools to consider when looking to go after this huge project.

Six Sigma is first and foremost when it comes to quality control and other quality management opportunities. Its popularity has sky-rocketed since its creation in the late 1980s. First developed by a desperate and frustrated quality control team, Six Sigma is an ideology that aims to reduce the number of product defects as close to zero as possible. More specifically, Six Sigma considers that any manufacturing process making more than 3.4 defects per million products is incurring too much waste and is therefore inefficient.

The changes that Six Sigma requires are significant; this is a method that is a long-term solution, and since it’s such a complex, expansive concept, it’s a good idea to hire a Six Sigma expert to help with implementation. Aside from that, the following are some additional tools to help get your Six Sigma project going to achieve quality control bliss!


Associated closely with Six Sigma, the DMAIC methodology is comprised of five phases:

  • Define the system, the expectations of customer, project goals, etc. specifically. Well-defined goals and expectations mean product specifications are clearer and more consistent.
  • Measure key aspects of the current process and collect relevant data; calculate the “as-is” process capability.
  • Analyze data to confirm cause-and-effect relationships. Determine what causal relationships are; take all actions possible to ensure all conditions and special circumstances have been considered and accounted for. Seek out root cause of the defect under investigation.
  • Improve current process using data analysis as basis for improvement. Techniques like design of experiments, poka yoke, and mistake proofing. Experiment with pilot runs to establish process capability.
  • Control the processes to ensure that any aberrations are corrected before they turn into defects.

Value Stream Mapping

VSM is a process that maps all the steps involved in making a product. It reveals where waste occurs. The wase that should be sought out includes:

  • Excessive inventory
  • Long wait times
  • Slow uptimes
  • Excessive setup times
  • Poor quality assurance

Finding these areas of waste and solving those problems will ensure the quality of the product is satisfactory, and it allows the company to see where improvements are required.

CTQ Tree

Critical-to-quality trees are figures that help companies translate customer needs into actionable production specifications. Used as a part of Six Sigma, CTQ trees help prioritize customer requirements to focus on quality and eliminating wasteful activities.

5 Whys

Usually used in the analyze phase of Six Sigma, this strategy of asking “Why?” five times helps get to the root cause of production problems. The first “why is the problem at hand whereas the last why symbolizes the root cause of the problem.

This strategy is essential to finding problems within a Six Sigma method. And again, solving that problem enhances the quality of not only the end product, but also the work that is being done.


Quality control is a vital part of any business, and the concepts that were mentioned in this article can, and will, help decrease defects and improve overall efficiency. Change is hard, but the change it takes to improve quality and QA testing strategies have benefits that will yield rewards for years to come.

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