What is Continuous Integration (CI) and Continuous Delivery (CD), and how do they relate to automation testing?

 Continuous Integration and Continuous Delivery are the set of practices that development teams use to handle code changes in reliable and efficient way.It is generally used by Devops team.Continuous  Integration is a practice of automating the integration of code. Continuous Delivery is a process carried away after Continuous Integration to make sure we can release the new changes error free to the customer.

Benefits of CI/CD:

1.Risk Reduction:It reduces the risk of major failures and downtime as continuous deployment process allows developer to fix issues early.

2.Quality Improvement:It improves the overall quality of software.Automated testing in CI/CD pipelines helps identify bugs, regressions, and integration issues early in the development cycle.

3.Enhanced Security:Security updates and patches can be applied more quickly.

4.Increased Collaboration: CI/CD promotes collaboration among development, testing, and operations teams.

5.Rollback and Recovery:CI/CD pipelines include rollback mechanisms allowing the user to revert to previous version of application.

Automation Testing and CI/CD:

Automation Testing in CI:

Unit,Integration and other types of testing are executed automatically whenever any changes in code are integrated.In case of failure CI can block thecode integration process.

Automation Testing and CD:

Automation testing can be performed for system testing and user acceptance testing.It can also perform security testing and non functional testing.

Thus automation testing plays a vital role in CI/CD process.

Spiral model

Spiral Model:

                                                                    Fig. Spiral Model

The Spiral model was developed by Barry Boehm in 1986.In this model we start with small,define important features of an application, implement them and get feedback on the implemented part of an application.This process is repeated until we develop a complete final product.

The different steps involved are :

1.Determine Objectives and Constraints.

2.Identify and Resolve risks.

3.Develop  and test current level.

4.Plan the next iteration.

5.Decide approach of next level.

Advantages:

1.Suitable for large projects.

2.Easy to estimate the cost.

3.Suitable for frequently changing requirements.

4.Avoidance of risk is enhanced.

Disadvantages:

1.Not suitable for small projects.

2.High expertise is required for risk analysis.

3.More documentation.

What is Waterfall Model

Waterfall Model is the Sequential model.In this model output of one phase becomes input of next phase.The review meeting is held before moving to next phase.There is no overlapping.Testing is done only after coding phase is finished.
The different phases are as follows:
1.Requirement Analysis:
All the requirements are collected and analyzed in this phase and then documented in SRS.
2 Design;
After the requirements are analyzed design is prepared  in this phase.The High level design and Low level design documents are prepared.
3.Coding:
Each unit is developed and later on integrated to develop a system.
4.Testing:
Once the coding is finished in this phase we perform the testing activity.Different  kinds of testing are performed as specified in  the scope of Test Plan.
5.Deployment:
In this phase the product is deployed in client location.
6.Maintenance:
In this phase the issues related with client environment are handled.It may include small changes the client wants. 

List Different SDLC Models

The different SDLC models are:

1.Waterfall Model
2.Spiral Model
3.Verification and Validation Model
4.RAD Model
5.Agile Model