V Model Iin Software Testing

V Model in Software Testing

The V-model is a unique kind of SDLC model where processes run consecutively in a V-shape. The Verification and Validation Model is another name for it. Its foundation is the correlation of a testing stage with each relevant step of development. Only after the preceding phase has been completed, i.e., there is a testing activity matching each development activity, does the following step begin.

Must-Know Software Testing Terms 

Software Development Life Cycle, or SDLC. To design and create high-quality software, developers must complete a series of tasks.

Software Testing Life Cycle, or STLC. It includes a series of tasks completed methodically by Testers to evaluate your software application.

Waterfall Model: The waterfall approach is a sequential framework for organizing the many stages of software development. Each stage is created to carry out a particular activity. In a waterfall paradigm, testing doesn’t begin until the system has been fully implemented.

The Issues of the Waterfall Model

As you may have noticed, testing in the model doesn’t begin until implementation is complete.

  • When working on a large project with complicated systems, it’s simple to overlook important information during the requirements phase. 
  • If you manage to note the requirements correctly but make serious mistakes in the design and architecture of your software, you will have to redesign the entire software to correct the error. 
  • In such cases, the client will receive an entirely incorrect product, and you may have to restart the project.
  • According to evaluations of thousands of projects, flaws introduced during requirements and design account for about half of all defects.

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Solution : The V Model

With each phase of the development life cycle having a matching testing phase, the V model of testing was created to allay this worry.

Left Side: SDLC, or Software Development Life Cycle, is on the model’s left side.

Right Side: Software Test Life Cycle, or STLC, is on the model’s right side.

The V Model: The V-model gets its name from the fact that the complete form resembles a V.

Check out the figure below to understand the V Model in STLC

V Model In Stlc

The left side depicts the development activities in a typical development process, and the right side depicts the testing activities. It shouldn’t be a mistake for me to assert that verification and validation are carried out alongside the real development activities during the development phase. Let’s now explore the picture:

Left-Hand Side

As was previously stated, development activities are on the left. Normally, we wonder what testing we can accomplish during the development phase, but the beauty of this approach is that it shows testing is possible across all stages of development activities.

Requirement Analysis : The requirements are gathered, examined and investigated during this stage. It is not crucial to hear how the system is constructed; what is relevant is what the system is intended to accomplish. To make the objectives apparent, brainstorming sessions, walkthroughs, and interviews are conducted.

  • Verification Activities: Reviews of the requirements are verification actions.
  • Validation Activities: Creating UAT (User Acceptance Test) test cases is a validation activity.
  • Artifacts Delivered: UAT test cases and a document outlining requirements.

System Requirements : The software’s high-level design is developed during this phase. The team researches and looks into potential ways to apply the requirements. The requirements’ technical viability is also investigated. The group also determines the required hardware and software, as well as the modules that will be built.

  • Verification Activities: Reviewing designs
  • Validation Activities: Planning and writing of system test cases, measurement of traceability
  • Artifacts Delivered: System test plans, test cases, hardware-software specifications, modules that need to be developed, etc.

Architectural Design : This stage sees the creation of the software architecture based on the high-level design. This stage sees the completion of the modules, their connections, dependencies, architectural diagrams, database tables, and technical details.

  • Verification Activities: Reviewing Designs
  • Validation Activities: Test cases and an integration test plan.
  • Artifacts Delivered: Designs for database tables, an integration test strategy, test cases, etc.

Module Design

Each and every software module is uniquely designed during this phase. In this stage, all methods, classes, interfaces, data types, etc. are completed.

  • Verification activities: Activities for verification design reviews
  • Validation activities: Unit test case creation and review are validation operations.
  • Artifacts produced: Generated artifacts include unit test cases

Code Implementation

The real coding is completed during this stage.

  • Verification activities: Activities for verification Review of test cases and code
  • Validation activities: Making functional test cases is a validation activity.
  • Artifacts Delivered: Test cases and a review checklist were developed as artifacts.

Right Hand Side

The Validation Phase’s testing operations are shown on the right-hand side. We’ll begin at the bottom.

Unit Testing

All unit test cases produced during the Low-level design step are executed during this stage. A code snippet is generated that runs a method (or any other piece of code) to test if the code snippet is producing the intended output or not. This technique is known as unit testing and is a type of white box testing. The development team is mainly responsible for this testing. Defects are recorded and tracked in the event of any anomalies.

Artifacts Delivered: The results of unit test execution

Integration Testing

The integration test cases that were developed during the architectural design phase are run during this step. Defects are recorded and followed up on in the event of any irregularities. Integration testing is a process where unit-tested modules are combined and tested to see if the combined modules produce the desired outcomes. To put it another way, it verifies that the application’s parts interact as intended.

Artifacts Delivered: The results of the integration test execution

System Testing

The system test cases, functional test cases, and nonfunctional test cases are all run during this phase. In other words, this is where the program is actually and thoroughly tested. Defects are recorded and followed up on to be fixed. Another important aspect of this phase is progress reporting. To verify the level of coverage and risk reduction, the traceability metrics are updated.

Artifacts Delivered: Test logs, defect reports, test summary reports, and up-to-date traceability matrices are all included.

User Acceptance Testing

Business requirements testing and acceptance testing are fundamentally related. Here, testing is carried out to confirm that the user environment complies with the business requirements. In this phase, there may also be compatibility testing and occasionally non-functional testing (load, stress, and volume testing).

Artifacts Delivered: Updated business coverage matrices and UAT results.

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When to use V Model in Software Engineering?

The V model is appropriate when

  • The criteria are clearly stated and not unclear.
  • Acceptance standards are clearly stated.
  • It is a small to medium-sized project.
  • The tools and technologies employed are static.

V-Model Principles :

From large to small: In the V-Model, testing is carried out from a hierarchical perspective. For instance, the project’s High-Level Design and Detailed Design phases are created using requirements determined by the project team. When each one of these stages is completed, the specifications they are laying out get more detailed and precise.

Data/Process Integrity: According to this concept, for any project’s design to be successful, data and processes must be integrated with one another. There must be a list of the process components for every need.

Scalability: According to this principle, the V-Model concept is flexible enough to support any IT project, regardless of size, complexity, or duration.

Cross-referencing: It is the process of establishing a direct link between requirements and the related testing activities.

Tangible Documentation: This idea states that each activity must give tangible documentation. Both the support staff and the project development team must use and adhere to this documentation. Documentation is used to maintain the program once it is made available in a production server.

Advantages of the V Model in Software Testing :

  • Stages are finished one at a time under this model, which needs extreme discipline.
  • Small projects with specified project criteria are used in the V-Model.
  • Simple, clear, and convenient to use.
  • This paradigm emphasizes verification and validation tasks early in the life cycle, increasing the likelihood of producing a flawless product.
  • It enables project managers to precisely follow development.

Disadvantages of the V Model in Software Engineering :

  • High uncertainty and danger.
  • Complex and object-oriented projects should not use it.
  • It is not appropriate for projects with unclear needs and a high chance of change.
  • Phase iteration is not supported by this model.
  • Concurrent events are challenging for it to manage.


Different development life cycle models exist. The development model used for a project depends on its objectives and ambitions. The project’s chosen development model must be adjusted for testing, which is not a stand-alone operation. Any model should undergo testing from the requirements stage all the way up to maintenance. If you are interested in learning V Model thoroughly, Join SLA for the Best Software Testing Training in Chennai.