In the field of Software testing we use different types of Software Testing Methodologies.
In the Software Development Process different software development approaches are used. A software development process also known as a Software Development Life Cycle (SDLC).
Each process model has its own advantages & disadvantages, the choosing of model is based on the requirement & need of your project to do the success in process of software development.
Here are the few commonly used Software Development Life Cycle used in actual testing:
- Waterfall Model
- V Model
- Agile Model
- Spiral Model
- RAD Model
1. Waterfall Model
The Waterfall Model approach is most basic life cycle model, which is the first Process Model begins and used broadly in Software Development to make sure project success. This model is developed by Winston Royce in the early 1970. Waterfall model is software development process sequential process, as flowing progressively downwards like waterfall via multiple phases & these simple sequence of phases has its own defines activities and goals. The Waterfall model is divided into following separate phases:
- Requirement Gathering & Analysis phase,
- Software Design,
- Implementation and Testing
- Maintenance
All these phases are the sequential phases & next step is totally depends on the previous step, so that second phase is begins as only if the defined set of objectives and goals are completed first.
Diagram of Waterfall model:
In the V Model Software Development Life Cycle, based on same information(requirement specification document) the development & testing activity is started. Based on the requirement document developer team started working on the design & after completion on design start actual implementation and testing team starts working on test planning, test case writing, test scripting. Both activities are working parallel to each other. In Waterfall model & V-model they are quite similar to each other. As it is most popular Software Testing Life Cycle model so most of the organization is following this model.
The V-model is also called as Verification and Validation model. The testing activity is perform in the each phase of Software Testing Life Cycle phase. In the first half of the model Verification testing activity is integrated in each phase like review user requirements, System Design document & in the next half the Validations testing activity is come in picture.
Typical V-model shows Software Development activities on the Left hand side of model and the Right hand side of the model actual Testing Phases can be performed.
In this process “Do-Procedure” would be followed by the developer team and the “Check-Procedure” would be followed by the testing team to meets the mentioned requirements.
In the V-Model software development life cycle different steps are followed however here we will taking a most common type of V-model example. The V-model typically consist of the following phases:
1. Unit Testing: Preparation of Unit Test Cases
2. Integration Testing: Preparation of Integration Test Cases
3. System Testing: Preparation of System test cases
Diagram of V model:
3. Agile Model
Agile development model is also a type of Incremental Model. Software is developed in incremental, rapid cycles. This results in small incremental releases with each release building on previous functionality. Each release is thoroughly tested to ensure software quality is maintained. It is used for time critical applications. Extreme Programming (XP) is currently one of the most well known agile development life cycle model.
Diagram of Agile model:
3. Spiral Model
The spiral model is similar to the increment model, with more emphasis placed on risk analysis. The spiral model has four phases: Planning, Risk Analysis, Engineering and Evaluation. A software project repeatedly passes through these phases in iterations (called Spirals in this model). The baseline spiral, starting in the planning phase, requirements are gathered and risk is assessed. Each subsequent spirals builds on the baseline spiral.
Planning Phase: Requirements are gathered during the planning phase. Requirements like ‘BRS’ that is ‘Business Requirement Specifications’ and ‘SRS’ that is ‘System Requirement specifications’.
Risk Analysis: In the risk analysis phase, a process is undertaken to identify risk and alternate solutions. A prototype is produced at the end of the risk analysis phase. If any risk is found during the risk analysis then alternate solutions are suggested and implemented.
Engineering Phase: In this phase software is developed, along with testing at the end of the phase. Hence in this phase the development and testing is done.
Evaluation phase: This phase allows the customer to evaluate the output of the project to date before the project continues to the next spiral.
Diagram of Spiral model:
4. RAD Model
RAD model is Rapid Application Development model. It is a type of incremental model. In RAD model the components or functions are developed in parallel as if they were mini projects. The developments are time boxed, delivered and then assembled into a working prototype. This can quickly give the customer something to see and use and to provide feedback regarding the delivery and their requirements.
The phases in the rapid application development (RAD) model are:
Business modeling: The information flow is identified between various business functions.
Data modeling: Information gathered from business modeling is used to define data objects that are needed for the business.
Process modeling: Data objects defined in data modeling are converted to achieve the business information flow to achieve some specific business objective. Description are identified and created for CRUD of data objects.
Application generation: Automated tools are used to convert process models into code and the actual system.
Testing and turnover: Test new components and all the interfaces.
Data modeling: Information gathered from business modeling is used to define data objects that are needed for the business.
Process modeling: Data objects defined in data modeling are converted to achieve the business information flow to achieve some specific business objective. Description are identified and created for CRUD of data objects.
Application generation: Automated tools are used to convert process models into code and the actual system.
Testing and turnover: Test new components and all the interfaces.
