Software development classic flowchart
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One, waterfall model
Model diagram
Definition: The Waterfall Model defines the various activities of the software life cycle as several phases connected in a fixed sequence, shaped like a waterfall, and finally a software product is obtained.
Status: This is a classic model that provides a basic framework for software development.
- Advantages:
1) Clear division of each stage
2) Emphasis on planning and demand analysis
3) Suitable for product development with stable demand - Disadvantages:
1) Single process, irreversible
2) The risk is revealed late and there are few opportunities for correction
3) The test is only one of the stages and lacks the whole process of test thinking
2. V model
Model diagram
Definition: RAD (Rap Application Development, rapid application development) model is an important model in the software development process. Because its model is similar to the letter V, it is also called the V model of software development. It shortens the development cycle and improves development efficiency by means of simultaneous development and testing.
- Advantages: Compared with the waterfall model, the V model test can enter the development stage as soon as possible.
- Disadvantages: Although testing enters the development stage as soon as possible, the real software testing is after coding. This neglects the requirements analysis and system design verification of the test, and the time efficiency is greatly reduced.
Three, W model
Model diagram
Definition: W model, proposed by Evolutif company. Compared with V model, W model adds verification and confirmation activities simultaneously in each phase of software development. As shown in the figure, it is composed of two V-shaped models, which represent the testing and development process respectively. The figure clearly shows the parallel relationship between testing and development.
- Advantages: Compared with the V model, the W model enters the development stage earlier in the test, and is parallel to the development stage. Problems are found earlier and can be solved in time. The division of labor in each stage is clear, which is convenient for management.
- Disadvantages: The W model is sequential and irreversible. It is still inconvenient to change and adjust requirements.
Four, agile development model
Flow chart
Definition: It has gradually attracted widespread attention since the 1990s. It is a human-centered, fast iterative, and gradual development method. Emphasize people-oriented and focus on delivering software that is valuable to customers. It is a framework for developing and maintaining complex products. It is to divide a large project into multiple small projects that are connected with each other, but can also be run independently, and completed separately. During this process, the software is always in a usable state.
- Advantages: Agile really means that the project enters the iterative phase of substantial development, and users will soon be able to see a baseline architecture version of the product. Agile focuses on market rapid response capabilities, that is, specific response capabilities, and high customer satisfaction in the early stage.
- Disadvantages: However, Agile pays attention to personnel communication and ignores the importance of documentation. If the project personnel flow is too large, it will bring a lot of difficulty to maintenance. When there are more novices in special projects, older employees are more tired. It requires people with more experience in the project, or it is easy to encounter bottlenecks in the project.
refers：
https://www.cnblogs.com/qiaoli0726/p/14167524.html