Jobs of QA in SDLC

Introduction to QA
Do you think the objective of the QA is to discover bugs or the objective of the QA is to discover bugs as early as possible?  The objective of the QA is to discover the bug as early as possible and ensure they get fixed.
After World War II when the weapons were tested before they come into action, The Quality Assurance term was introduced

The difference between QA and QC
Quality Assurance refers to the planned and methodical method for observing the quality of the process which is followed to maintain the quality of the product. QA is proactive and assumes significant jobs in each period of SDLC.
Quality Control finds the defects in the product. The procedure set by QA is trailed by QC to meet the expectation. QC additionally named as an analyzer/tester, who discover the bugs. They depend on the test cases prepared by QA. QC is the subset of QA.

Jobs of QA in SDLC
As we probably am aware QA assumes a significant job in each period of SDLC (Requirement Analysis, Design, Development, Testing and Deployment/Documentation). Here, I will clarify how QA works in each period of SDLC.

1. Requirement Analysis

• Possibility of investigation of the Requirement 
• Hazard/Risk Analysis/Forecasting 
• Bug Prevention/Mitigation 
• Distinguishing escape clauses/Identifying loop holes
• Properly express functional requirements and review the gap between features so that they can be analyzed as early as possible.
• Build up/Establish the environment requirements
• Set up the more significant level test plan including the risk and tools used in the project. 
• Set up defect tracking methodology. 
• Identify the type of the testing to be carried in the project.

2. Design

• Review the design, are they testable? How long will it take to test?
• Assuring architecture satisfies all (non)-functional requirements.
• Prepare the Data Flow Diagram (DFD) of the project and document it. Verify the flow of the functionalities.
• Verify the ER diagram, Process diagram, Use Case etc.
• Since QA is the proxy end user, they review the design as an end-user perspective. Verify the user type and the user interface/experience.
• Prepare the low-level test plan including risk, scope, tools, environment etc.

3. Development

• Maintain the algorithm for development.
• Develop the test case so that it can be used in TDD(Test Driven Development) or BDD (Behavior Driven Development).
• Arrangement of Environment for testing

4. Testing

• Confirm the test is run according to the test plan. 
• Execute the test case 
• Testing is also known as defect detection phase, in this phase, we find the defect and report them as early as possible.
• Check the bugs are fixed before release
• Perform the following testing and assure that no defects remain in the project.
• Functional Testing
• Test Automation
• Integration Testing
• Regression Testing
• Performance Testing
• Security Testing
• User Acceptance Testing (UAT)

5. Deployment/Documentation

• Set up every single standard Guide and Manual and ensure nothing has been left behind which can make an issue with software deployment.
• Prepare the user guide/manual of the product.