The cascade model uses an approach “top-down”, regardless of whether it is used for software development or testing. The main steps involved in this method of software testing are:
- The analysis of needs
- Test design
- Test of the implementation
- Testing, debugging and verifying of code or product Implementation and maintenance
In this method, you proceed the next step only after you have completed the previous one. The model uses a non-iterative approach. The main advantage of this method is its simplistic, systematic and orthodox approach. However, it has many disadvantages, such as bugs and errors in the code that won’t be discovered until the testing phase. This can often lead to the loss of time, money, and other valuable resources.
This method is based on the selective combination of sequential and iterative approaches, in addition to the large variety of new methods of the development. Fast and progressive development is one of the key principles in this methodology. The emphasis is made on the obtaining quick, practical, and visible outputs. Continuous interaction with customer and participation is an integral part of the entire development process.
Rapid Application Development (RAD)
The methodology of the application’s rapid developing. The name speaks for itself. In this case, the methodology adopts the rapid evolutionary approach, using the principle of component construction. After understanding of different requirements of this project, a quick prototype is prepared, and then it is compared with the expected set of output conditions and standards. Necessary changes and modifications are made after joint discussion with the customer or with team of the developers (in the context of software testing). Although this approach has its share of advantages, it can be not appropriate if the project is large, complex, or has an extremely dynamic character, in which requirements are constantly changing.
The spiral model
As the name implies, the spiral model is based on the approach in which there are a number of cycles (or spirals) of all sequential steps in the cascade model. After the initial cycle is completed, the thorough analysis and the review of the achieved product or output are implemented. If the output does not meet the specified requirements or expected standards, the second cycle is performed, and so on.
Rational Unified Process (RUP). The rational unified process
The RUP methodology is also similar to the spiral model, in the sense that the entire testing procedure is broken into several cycles. Each cycle consists of four stages – creation, development, construction, and transition. At the end of each cycle, the product/output is reviewed, and then the cycle (consisting of the same four phases) follows if necessary. The application of information technology is growing every day, as well as the importance of proper testing services companies has grown significantly. Many companies keep for this purpose the state of special teams, the possibilities of which are at the level of the developers.