Difference Between Quality Assurance and Quality Control

Providing a high-quality product in today’s competitive market is not optional but essential. Companies do depend on clearly defined quality processes to ensure customer satisfaction and long-term success. Quality Assurance (QA) and Quality Control (QC) are two of the most important components of quality management. Both QA and QC refer to specific activities in the quality management lifecycle, and there are important differences in purpose, role, and their working relationship needed to build systems. In this blog, you will explore quality assurance and quality control differences in detail and how both contribute to building a reliable quality management framework.

Table of Contents:

• What is Quality Assurance (QA)?
• What is Quality Control (QC)?
• Difference Between Quality Assurance and Quality Control
• Key Principles of Quality Assurance and Quality Control
• Activities of Quality Assurance and Quality Control
• Examples of Quality Control and Quality Assurance in Different Domains
• How QA and QC Work Together in the Quality Management Process?
• Tools and Techniques Used in QA and QC
• Best Practices in QA and QC
• Challenges in QA and QC
• Conclusion

What is Quality Assurance (QA)?

Quality Assurance (QA) is a preventive process, focused on building quality from the start. Instead of checking the final product, QA works from the early stages to make sure that every step in the process is efficient, consistent, and correct. Its main goal is to avoid defects by improving the process, not just inspecting the results.

Quality Assurance is a structured approach. This involves setting a quality goal, planning for the quality practices, being involved in the current activities, and improving the processes. Quality Assurance can be applied to any phase of development or production (planning, design, implementation, product delivery, etc.) and used throughout a process. 

What is Quality Control (QC)?

Quality Control (QC) is a corrective and product-based process. It aims at finding defects in the end product and ensuring they are fixed. QC is reactive to quality defects, whereas QA is preventive and process-based. QC ensures that the product fits the customer’s requirements or the specification set out before manufacturing. 

QC involves checking, testing, and validating the process. QC operations aim to make changes according to the specification. QC is reactive and usually occurs after the production or development process. If defects are identified through QC, they should either be corrected or rejected. The QC process should deliver a product that meets customer expectations, regulations, and specifications.

Difference Between Quality Assurance and Quality Control

Now, let’s understand in detail what is the difference between quality assurance and quality control.

Key Principles of Quality Assurance and Quality Control

Understanding the core principles behind quality assurance and quality control helps organizations build robust systems that minimize defects and maximize customer satisfaction.

Principles of Quality Assurance

Let’s explore the quality assurance:

1. Prevention over detection

QA is about the prevention of defects before they occur, by making improvements to the process. Quality Control is about the identification of defects when they occur.

2. Process orientation

QA is mainly about improving the production or development process. Because only a structured process can increase the quality of the outcome.

3. Continuous improvement

A big component of QA is continuous evaluation of existing processes and improvement over time. This is about learning from past mistakes and optimizing processes regularly.

4. Customer focus

Quality has to be in alignment with customer needs and expectations. QA involves obtaining feedback from customers and applying it to product and process improvements.

5. Documentation 

QA actively encourages keeping proper documentation and using checklists. Guidelines are established to ensure consistency in executing the process.

Principles of Quality Control

Let’s explore the principles of quality control:

1. Detection of defects

QC mainly focuses on finding defects in the final product. Corrections are made in the defective items before delivering them to the customer. It also assures that the result is a defect-free product. 

2. Product orientation

QC directly inspects the physical or functional output of a process, whether it is a manufactured product, a software product, or a report from a healthcare practice. 

3. Testing and verification

Testing is one of the important processes in QC. It verifies if the product characteristics are compliant with the defined specifications. 

4. Specification compliance

QC measures the final product against specifications or standards like ISO, customer specifications. It ensures that an intended product is developed according to specifications. 

5. Corrective action

Whenever a deviation is found, QC processes initiate rework, rejection, or modification. Continuous feedback allows for improvement to product batches or releases.

Activities of Quality Assurance and Quality Control

To ensure defect-free outcomes, organizations follow structured activities as part of their quality assurance and quality control strategies:

Activities of Quality Assurance

Let’s explore the activities of quality assurance.

1. Process Audits

Examine internal processes to check if they are being done by defined standards and to look for improvement opportunities. Audits help in maintaining consistency and finding inefficiencies in the early stage.

2. Standard Operating Procedures (SOPs)

SOPs are written instructions about how to do routine tasks the same way every time. Minimizing variation across teams helps ensure consistent quality.

3. Training & certification

This ensures employees have the right skills, use up-to-date tools, and are aligned with quality standards. Training increases accountability and lessens the likelihood of errors in each role.

4. Code reviews 

Involves an examination of source code on the same team to find bugs, establish coding standards, and improve design. Code reviews establish collaboration among team members and help reduce technical debt by catching issues early.

5. Risk management planning

Identifies risks in processes or products and details how to manage them. Proactive planning minimizes disruptions and quality failures.

Activities of Quality Control

Let’s explore the activities of quality control:

1. Product inspections

The physical examination of the products has to be done to discover defects, damage, or misalignment. Inspection typically occurs at multiple phases during a product’s production to ensure accuracy.

2. Functional testing

Validates if a product or software is working correctly. This may include a feature check of all features, a user check of all flows that the user may navigate. This is done through a mechanical action to check against the requirements.

3. Statistical Quality Control (SQC)

Uses statistical techniques like control charts or sampling to keep track of quality trends. SQC processes help discover trends of recurrent defects and process variation.

4. End-of-Line testing

This is testing for completed products that go through a manufacturing line. It is a method to ensure the product is working or safe before leaving the line.

5. Defect reporting 

Provides recorded information on defective products, categorizes defects by type, and reasons for the defects. Feedback from reports should be used for improvement.

Examples of Quality Control and Quality Assurance in Different Domains

Here are some examples of how quality control and quality assurance are done in different sectors:

Examples of Quality Assurance

Let’s explore the examples of quality assurance:

1. Software Development 

QC for software is generally focused on functional and regression testing to ensure an application behaves as intended. Once the bugs are found, it is documented and tracked using tools like Jira.

2. Manufacturing 

QC involves inspecting physical items by using measurement tools and product sampling. Rejected items are removed from production, and corrective actions are implemented to ensure high quality and no customer disappointment.

3. Healthcare 

QC in healthcare involves ensuring accuracy by reviewing medical records, performance of diagnostic tools, and laboratory tests. The reviews are done to ensure reports are accurate and reliable.

4. Pharmaceuticals 

QC will make sure that drugs and medicines have met the purity and other safety standards. This includes lab testing, chemical analysis, and stability testing. Once these tests are successfully passed, the drug is approved for public use.

Examples of Quality Assurance

Below are some examples of how QA’s are done in different sectors:

1. Software Development

QA promotes software quality through the use of code reviews, automated testing, and compliance with development standards. QA helps identify bugs early on and maintain code quality throughout the software development lifecycle (SDLC).

2. Manufacturing

QA begins with establishing production standards, conducting repetitive inspection tests, and calibrating equipment. QA addresses how products perform against safety, durability, and compliance directives before they are delivered to the customer.

3. Healthcare

QA encompasses continuous clinical commitment, patient safety, and regulatory compliance (e.g., HIPAA). QA considerations include audits and quality measures, training of health staff, and monitoring of processes and systems.

4. Pharmaceuticals

QA determines whether the drugs have been created and manufactured in strict accordance with regulations (e.g., GMP). It provides expectations for a chain of documentation, lab testing, reflecting batch release into circulation, and guaranteeing safety.

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How QA and QC Work Together in the Quality Management Process?

QA and QC are separate yet interrelated components of an effective quality management system (QMS). They assure that both processes and products comply with established standards, customer requirements, and regulatory requirements.

1.  End-to-End quality assurance

QA takes responsibility for designing and improving processes that lead to quality outputs. QC accepts responsibility for determining if the end products of a process comply with requirements. 

2. Processes and products

QA establishes structured workflows, while QC tests the final product to make sure it is correct. They work together to ensure quality across both the process and the product. 

3. Feedback loop for improvement 

The findings of QC help QA in identifying the bugs in a system. The feedback is used to improve future processes and prevent repeated issues.

4. Shared responsibility across teams 

QA works on the planning and execution process, and QC verifies the work before it is released. While QA is focused on improvement and creating accountability, QC is concerned with accountability and a quality final product.

Learn what zero defects means in quality management and how to achieve it in this blog.

Tools and Techniques Used in QA and QC

1. Six Sigma

Six sigma is used to eliminate defects with a data-driven approach. This improves the quality. It uses DMAIC (Define, Measure, Analyze, Improve, Control) to improve processes.

2. Minitab

A statistical software program used to analyze and visualize quality data. It supports Six Sigma projects and helps in determining trends and root causes.

3. Lean management

Lean management is a method of eliminating waste and inefficiency in processes. Lean seeks to maximize value while using the least amount of resources by eliminating waste along the value stream.

4. Theory of Constraints (TOC)

A method that identifies the weakest link is known as its constraint. Focusing on its constraints, it improves productivity and product quality throughout the entire system.

Best Practices in QA and QC

1. Start QA early in the lifecycle

Incorporate QA early in the process during the planning and design phases, so that you can get rid of defects instead of getting rid of them reactively.

2. Automate when possible

Implement automated testing or audits through automation tools for repetitive work to enhance reliability.

3. Encourage collaboration between teams

Provide a healthy communication forum for QA, QC, development, operations, and all others, making quality a culture.

4. Train continuously

Training and certifications are an integral part of the application of continuous improvement in QA, and this can spark interest for the teams or new employees.

5. Use metrics and feedback

To fine-tune and improve the quality of the product over time, track the quality metrics and gather feedback. 

Challenges in QA and QC

1. Resource limitations

Insufficient time, budget, or skilled staff can weaken QA and QC processes. This may lead to rushed checks or skipped steps, increasing the risk of defects in the final product.

2. Resistance to change

Teams may resist the implementation of new quality processes or documentation standards. This can affect the realization of QA and adherence to the process.

3. Limited skilled workforce

QA and QC need trained professionals who understand tools, methodologies, and industry standards. In some cases,  due to skill levels, this reduces the impact of quality.

4. Poor communication

QA and QC teams working in silos means that process-related feedback, test results and other feedback may not be shared properly. This allows problems to keep on recurring.

5. Tool alignment issues

Using multiple tools across QA and QC without any form of alignment can continue to create silos of data.

Conclusion

QA and QC are both important to maintain high standards across industries. While QA focuses on process improvement to prevent defects, QC ensures the final product meets expectations. Together, they form a powerful combination in any quality management system. Whether you’re in software, manufacturing, or healthcare, balancing both is the key. With the right tools, training, and collaboration, organizations can achieve long-term consistency and customer satisfaction. Ultimately, quality assurance and quality control are not competitors, but they’re the twin pillars of any successful quality strategy.

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