SDLC / STLC

Question 1

What is Software Development Life Cycle?

Answer 1

• process used by developers to design, develop, and test high-quality software.
• aims to produce software that meets customer expectations, reaches completion within times and cost estimates, and is efficient and fault-free in operation.
• 6 distinct phases:
  Planning, Analysis, Design, Implementation, Testing & Integration, Maintenance

Question 2

SDLC Phases

Answer 2

• Planning - plan the entire project
• Analysis – understand requirements to map software onto that set of requirements
• Design – design a software solution to meet the requirements
• Implementation– build the software
• Testing and Integration – install into target environment and test
• Maintenance – adapt software to changing requirements and environment

Question 3

Waterfall Model

Answer 3

• first model of the software lifecycle
• Requirements > Analysis & Design > Implementation > Testing > Maintenance
• Must start with planning phase and ends with the maintenance phase
• No overlap: cannot move to the next phase until the current phase is complete.
• Forward direction only: no revisiting previous phases to fix problems.
• Achilles heel: rigidity and inability to address issues discovered in later phases.
• Results: potential for unresolved issues to cause project failure.

Question 4

Iterative Model

Answer 4

• Requirements > Design > Build > Test
• allow for revisiting and refining parts of the project through repeated cycles.
• project can be divided into subprojects with each focusing on specific parts or levels of the architecture.
• supports gradual development, starting from a high-level architecture to more detailed components.
• It enables addressing and fixing issues as they arise during testing of specific features or segments.
• restrictive for requiring a full cycle completion to address problems
• Recognized design issues during implementation could not be immediately fixed but required a new cycle, highlighting the model’s rigidity for modern development needs.

Question 4

Agile methods

Answer 4

• Respond to change quickly
• does not require completing one phase before moving to the next
• promote continuous work for the entire team leading to higher productivity and shorter delivery times.
• accommodate changes smoothly, even if parts of the software need to be re-implemented
  -Phases can happen simultaneously
  
  • Design can start once some requirements are finalized
  • Implementation can start once some design is finished
  • Test design can start once design is complete
  • Testing can start as soon as some coding is done

Question 5

Testing in the SDLC

Answer 5

You can test
 During requirements – test plan
 During design – unit test design
 During implementation – unit test implementation
 During testing
 During Delivery – acceptance tests
 During maintenance – regression testing and testing new features

Question 6

Incremental Development

Answer 6

• technique that builds software in pieces
• Other parts are constructed and added into the core
• Testing is done as new components are built and integrated into the whole

Question 7

Continuous Integration

Answer 7

• practice that enables developers to integrate their code changes into a central repository frequently.
• Developers:
  
  • Check it out to add features or fix bugs
  • Test it to make sure it is bug-free
  • Push it to the repository
    -The goal is to make sure that the code in the repository is bug-free
• CI flow ensures that the software being developed is robust, that bugs are caught early, and that the product remains in a state that is always ready for deployment. It emphasizes the importance of testing in maintaining software quality and efficiency in the development lifecycle.

Question 8

Test Driven Development

Answer 8

• writes the tests first and then the code to be tested
• test team usually gets together with the developers and
  -agrees on functions or classes and what they should do
• advantage of test driven development is that there are no surprises for the
  developers
• can be used as part of continuous integration

Question 9

The Software Testing Life Cycle

Answer 9

• series of steps to create and execute software tests
• Benefits of using the STLC :
  
  • provides a guide for the testing process, increasing efficiency and consistency,
  • clearly defines the expectations of each part of the project,
  • provide time constraints on the testing,
  • Ensures that software meets requirements before more software is developed,
  • Ensures that all project requirements are met.

Question 10

STLC Phases

Answer 10

• Requirement Analysis > Test Planning > Test Case Development > Test Environment Setup > Test Execution > Test Cycle Closure
• Requirements Analysis – requirements are examined to identify their testable aspects
  
  • Entry: A set of requirements and acceptance criteria
  • Exit: Requirements traceability matrix and an automation feasibility report
• Test Planning - produces the test plan document
  
  • Entry: the requirements analysis and requirements test matrix,
  • Exit: an approved test plan.
• Test Case Development - the actual test cases are created
  
  • Entry: an approved test plan.
  • Exit: approved test cases, test data, and automation scripts
• Test Environment Setup – the test environment is set up
  
  • Entry: system design and project architecture.
  • Exit: a functional test environment.
• Test Execution – tests are deployed to the testing environment and executed
  
  • Entry: all of the exit criteria from the previous steps.
  • Exit: the tests have been performed and test reports generated
• Test Cycle Closure - results in a report which summarizes the results of the tests
  
  • Entry: test results and reports.
  • Exit: test closure report