Difference Between Quality Assurance and Quality Control

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, we will explore the differences between QA and QC in detail.

Table of Contents:

What is Quality Assurance (QA)?

what is quality assurance

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. 

Key Principles of Quality Assurance

QA has a set of principles that are used by organizations to produce quality results consistently:

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, using checklists. Guidelines are established to ensure consistency in executing the process.

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Activities of Quality Assurance 

To ensure defect-free outcomes, there are a few activities followed by the organisation. Below are some key quality assurance activities:

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.

Examples of Quality Assurance in Diff

Quality Assurance work is different in every industry, but its objective is to improve processes and avoid defects. Below are some of the 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.

What is Quality Control (QC)?

what is quality control

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.

Key Principles of Quality Control

QC is guided by some basic principles that will help ensure that products meet desired levels of quality. Below are some of the key 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 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 Control 

Organizations implement many quality control activities to provide quality and defect-free products. Below are some of the key quality control activities:

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 in Different Domains

Quality Control varies by industry, just like QA. Below are some examples of how quality control is done in different sectors:

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.

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Difference Between Quality Assurance and Quality Control

Difference Between Quality Assurance and Quality Control
Parameter Quality Assurance Quality Control
Definition Quality Assurance (QA) is focused on the process of preventing defects during development. Quality Control (QC) is focused on the ability to find and correct defects in the product.
Focus QA focuses on continuous process improvement and standardization. Quality Control focuses on the overall testing and inspection of the product.
Objective The goal of QA is to ensure quality is designed into or built into processes from the start. The goal of QC is to check whether the final products meet the quality standards.
Work nature QA is an intervention based on the process, and it is ongoing. QC is an activity based on the product, and it is done in specific testing activities.
Duration QA can be done throughout the complete development or production process. QC can only occur after the product is developed or manufactured.
Responsibility QA is a shared activity that is done by all participants in the process. QC is typically performed by a distinct testing or inspection team.
Tools QA uses tools like process workflow diagrams, audits, and quality management systems (QMS). QC uses tools like test cases, checklists, control charts, and defect management systems.
Techniques Techniques may include various process audits, standard operating procedures (SOPs), training, and continuous improvement. Techniques include manual testing, automated testing, sampling, and validation processes.
Documentation QA focuses on detailed process documentation to create consistent and concise outputs. QC focuses on recording defects, testing outcomes, and quality inspection records.
Approach QA is preventative and strategic in approach. QC is corrective and operational in approach.
Result QA results in a robust, error-safe process. QC results in a defect-free, customer-ready product.
Salary QA professionals in India make on average between ₹4.5 LPA to ₹10 LPA based on experience and domain. QC professionals generally make on average between ₹3 LPA and ₹8 LPA based on experience and domain.
Performance metrics QA applies metrics such as process compliance, training, and the audit function. QC applies metrics including defect density, error rate, and test coverage.
Use case QA is applied in all development phases, i.e., planning, development, etc. QC is done on the output of the process before it is delivered or launched.

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.

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.

Which is More Important: QA or QC?

Quality Assurance (QA) and Quality Control (QC) both play a major role in ensuring the quality of deliverables. QA is more proactive, focusing mainly on preventing defects. On the other hand, QC is reactive, which mainly focuses on identifying and resolving defects.

In most industries today, QA will be considered slightly more important, since preventing a problem is more efficient and economical. It is always easier and cheaper to prevent a problem than fix it later on. QC is fundamentally important as it is the last line of defence against defects reaching customers. The reality is that both QA and QC will work together best, as part of a continuous feedback loop, for improving the quality of goods or services.

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, QA and QC are not competitors; they’re the pillars of quality. In this blog, you have gained knowledge on QA and QC in detail.

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Difference Between Quality Assurance and Quality Control – FAQs

Q1. Is QA better than QC?

No, they’re both important. QA prevents defects, while QC identifies and corrects them.

Q2. Can a company only use QC?

No. If a company doesn’t have QA, defects could continue to happen repeatedly and in an unplanned and poor process.

Q3. Which business sector needs QA and QC the most?

Software, manufacturing, pharmaceuticals, and healthcare are sectors that depend on both QA and QC.

Q4. Is testing part of QA or QC?

Testing is a QC activity. QA is about planning and controlling processes.

Q5. Do QA and QC jobs require different skills?

Yes, QA requires skills in processes, concepts, and planning. QC requires skills in inspection and technical evaluation.

About the Author

Senior Associate - Automation and Testing

Akshay Shukla, a senior associate at a multinational company, is an experienced professional with a rich background in cloud computing and software testing. He is proficient in frameworks like Selenium and tools like Cucumber. He also specialises in Test-Driven Development and Behavior-Driven Development.

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