About software development-iterative development

I haven't updated my blog for a long time. I feel that I am just lazy and don't want to write or do anything more meaningful. It is time to reflect on yourself and make some changes.
In April 10, I heard that the SRTP project of the school is about to be completed recently. Recently, I wrote a version. Although there are many shortcomings, I feel pretty good. Although it was just a few days, I still had a lot of experience in the development process. I hope to share with you.
The overall process of software development is basically Requirement Analysis-database analysis-system design-a loop of coding and restructuring-the project is over. However, the traditional waterfall development model is no longer applicable to the development trend, and the agile development model is deeply rooted in the hearts of the people. In this era where almost everyone thinks that a software that can work is better than a facial mask, everyone puts communication and iterative development with users first. Only by fully communicating with users can users know their needs and what they need, and only know what they need, the developed software is not as bad as the user's requirements.
Requirement is the first step. Although a user cannot say all the requirements at a time, or the user does not know what he wants before seeing the final software, even if the user knows this, requirements analysts and users have different understandings. However, it is necessary and necessary to design before coding. Although the design will change in the development process and will evolve with the highlighting of the details, a design with a reasonable granularity and clear structure can reduce the reconstruction problems, so that the design changes in the development process do not affect the project progress, or even affect the project's success or failure. Design is built on the basis of requirements. It can be seen that problems in any link between requirement-design-development are related to the success or failure of the project.
How can we reasonably grasp the relationship between the three? "The most unchangeable thing in software development is that the demand is always changing." Another point is that "the major functional requirements are the least changed ". Therefore, in the first round of iterative development, the design and coding of the most important functions are required, work-ready software is provided, and users can communicate with each other to see the results of their work, users will be given a clearer understanding of what they want. Second, they will be able to affirm the work of project members, help demand analysts get more comprehensive requirements, and designers will better grasp the system. In the second iteration, the main requirements identified during the first iteration are met, and so on. In this way, the entire development process involves both user participation and the cooperation of developers and designers. The final software must be what the users want.
Iterative development reduces the risk of user investment, reduces the risk of project failure, enhances user competitiveness, reduces development complexity, and enhances the ease-of-use and availability of the system.