Introduction

Quality Assurance (QA) is the process of making sure a product/service meets the required quality standards and works as expected before it reaches the customers

It ensures the application works correctly without any issues, the requirements are met and they identify the errors early. QA is not about finding errors but preventing it.

QA is done throughout the SDLC phase.

Types of QA

1. Preventative QA – It prevents any errors from happening in the first place

2. Detective QA – It identifies if any error has occurred before it reaches to the customers.

3. Corrective QA – It rectifies problems that has already occurred. Analyses the root cause for that issue and resolve it.

4. Assessment QA – It evaluates and verify the overall QA processes and ensures that it have continuous improvement, follows standards and requirements.

QA vs QC

Process vs Product oriented

Quality Assurance (QA) - Process oriented

QA concerned with processes, standards and methodologies.

Example:

• SDLC followed correctly

• Test strategy prepared

• Review conducted?

• Product documentation maintained?

It does not test the product. It improves the process so defects don’t occur.

Quality Control (QC) - Product oriented

QC concerned with actual Software / Product.  It identifies the defects in the finished work.

Example:

• Does the login work?

• Is there is any bug?

Types of Testing

1.     Manual Testing

2.     Automation Testing

Manual Testing

Here testers write test cases manually without using any automation tools. The testers play a role of end user and checks whether the application works as expected.

Automation Testing

It uses tools and scripts to execute test cases automatically.

• Testers write test scripts using tools.

• Scripts executed automatically

• Results generated by the tool

Tools - Selenium, Jest, Junit, Pytest, etc... 

Functional vs Non – Functional Testing

Functional Testing

Functional testing checks WHAT the system does.

 It verifies whether the application works according to the requirements or not.

Types

• Unit Testing

• Integration Testing

• System Testing

• Smoke Testing

• Sanity Testing

• Regression Testing

• User Acceptance Testing

Non-Functional Testing

Non-Functional testing checks HOW the system performs. It validates the speed, performance and scalability.

Types

• Performance Testing

• Load Testing

• Stress Testing

• Security Testing

• Usability Testing

• Reliability Testing

• Scalability Testing

• Compatibility Testing

Severity vs Priority

Severity

Means - How severe the defect is?  Impact of the defect on the application.

Decided by: Tester

Common Severity Levels:

• Critical – App crash, data loss

• High – Major feature not working

• Medium – Feature works partially

• Low – UI issues (alignment, spelling)

Example: Login not working -> High / Critical

Priority

How fast it should be fixed?

Decided by: Product owner / Manager

Common Priority Levels:

• P1 (High) – Fix immediately

• P2 (Medium) – Fix in next build

• P3 (Low) – Can wait

Example:

• Login issue before release -> P1

• Spelling mistake -> P3

Verification vs Validation

Verification

• Verification is the process of checking documents, design, and code without running the application.

• It ensures that the product is built according to given requirement and specifications. Done before testing and Prevent errors.

Validation

• Validation is the process of testing the actual application by executing it to ensure it meets user needs.

• Done after development. It detects defects.

Defect Lifecycle

It is a journey of the defect from the time it is found by a tester until it is fixed, verified, and closed.

New → Assigned → Open → Fixed → Retest → Verify → Closed

Alternate Defect States

Rejected / Duplicate / Deferred / Not Reproducible / Reopened

Explanation

New – Tester finds defect during testing -> Logs it in defect tracking tool -> Status set to New.

Assigned – Defect reviewed by Test Lead / Project Manager -> Assigned to developers -> Status set to Assigned.

Open – Developer starts working on the defect -> Status is changed to Open.

Fixed – Developer fixes the defect -> Status changed to Fixed.

Retest – Tester retests the defect in the new build -> Status set to Retest.

Verified – Tester confirms defect is fixed -> Status changed to Verified.

Closed – Tester closes the defect -> Status set to Closed.

Rejected – Defect is invalid.

Duplicate – Same defect already logged earlier. So, new defect is marked as Duplicate.

Deferred – Defect is valid but postponed and will be fixed in future release.

Not Reproducible – Developer cannot reproduce the issue and needed more steps and details from the tester.

Reopened – After retest, if the defect still exists or new issue caused status set to Reopened.

Conclusion

QA plays a major role in developing high-quality software by makes sure that all requirements are met, processes are followed, preventing errors and makes sure there is continuous improvement. When teams understand testing techniques and defect management concepts, they can reduce production issues and deliver better results.