By reading the requirements engineering, I think the main question is how to do and what to do. The transformation of what and how. By reading the article and other people's blogs, I think these words are very good to say: to explore the needs, limit demand, guide the needs, control requirements.
Through the business needs, user needs, functional and non-public energy requirements, through the process, the use of technology to finally make their own required technology.
In this book, the Small library information management system, is the use of UML modeling, to determine the system's participants, scenarios, system use cases, use cases of the relationship between the final writing use case description document. In each step, we think about the function of the system, who wants to use the system as a way to get information, using the matching scene interface to determine how much of the use case is finally written.
I think this chapter has a very important effect on us.
The theory, method and practical needs of software engineering