Software Development Life Cycle (SDLC)

Software Development Life Cycle (SDLC)

• SDLC emerged as a response to the initial lack of structure in software development
• It's a structured approach to developing software, defining distinct phases.

SDLC Phases

• Planning: Planning the entire project; outlining the scope, goals, and resources.
• Analysis: Understanding the project's requirements to map the software.
• Design: Designing a software solution to meet the defined requirements; includes detailed specifications and architecture.
• Implementation: Building the software based on the design specifications.
• Testing & Integration: Installing the software in the target environment, performing various tests to identify and resolve bugs, and ensuring successful integration.
• Maintenance: Adapting the software to changing requirements and environments; includes ongoing updates, bug fixes, and performance enhancements.

Models of Software Development

• Waterfall Model: A sequential model where each phase must be completed before the next one begins.
• Iterative Model: A cyclical model where development occurs in iterations (cycles). Each iteration focuses on adding functionalities and addressing changes based on test results.
• Agile Models: Models that emphasize flexibility and responding to change quickly; multiple phases can happen simultaneously. Changes to requirements are not seen as a problem, but an opportunity.

Testing within SDLC

• Testing is integrated throughout the project's lifecycle: During requirements, design, implementation, testing, delivery, and maintenance.
• Types of testing: unit tests, integration tests, acceptance tests, and regression tests.

Incremental Development

• The system's core is built; additional parts are constructed and integrated one at a time.
• Testing occurs concurrently with new component integration.

Continuous Integration (CI)

• Working software kept in a repository.
• Developers continuously check-in code, test, and push updates to the repository.
• This ensures consistent integration of changes and quick resolution and detection of bugs.

Test Driven Development (TDD)

• Tests are written before the code they're designed to test.
• Aligns developers and testing teams early in the development process and reduces unexpected issues down the line.
• Helpful in ensuring that the functionalities and classes are designed according to the intended purpose early on.

Software Testing Life Cycle (STLC)

• A structured approach to the software testing process, guiding the activities.
• STLC phases: requirement analysis, test planning, test case development, environment setup, test execution, test closure.

STLC Benefits

• Increased efficiency and consistency in the testing process.
• Clearly defined expectations for each testing phase.
• Defined time constraints for testing.
• Ensures that software meets requirements before more development.
• Ensures all project requirements are addressed.

STLC Phases (Detailed)

• Requirements Analysis: Identifying testable aspects of requirements. Output includes a requirements traceability matrix and an automation feasibility report.
• Test Planning: Creates the test plan document based on requirements and test matrices. Output includes an approved plan.
• Test Case Development: Constructing the test cases, test data, and automation scripts. Output includes approved test cases, and scripts.
• Test Environment Setup: Establishing the testing environment to ensure accurate simulation of target environment. Output is a functional testing environment.
• Test Execution: Deploying tests in the testing environment and performing them. Output is the performance of tests and generated reports.
• **Test Cycle Closure:**Summarizing test execution results and producing a closure report. Output includes a test closure report.

Requirements Traceability Matrix (RTM)

• A document that tracks the relationships between requirements and test cases.
• Ensures that every requirement is tested and documented.