--Originally published at Newbie Programmer
The chapter two is interesting, this continues and introduces new concepts of the first chapter of how to make a good software, because explain the huge importance of the requirements.
The requirements are things that the system, project, app must have to do and work correctly in base of what the client wants. Its important to make a list of the needs, because in the process of making the product the client should have more things in mind of how they can work better with the project, another thing that is important is to write requirements in the view of the customers or users of the application, because your client uses the product different from the final user, for example in the book is the dog, in this phase you have to think beyond the requirements and prevent changes in the process.
Despite of having good requirements its a must to prevent the final product from unusual scenarios, to have a plan when the things goes wrong, in this case we can make alternative paths to solve problems, this scenarios can be explained as use cases, this use case are the different goals, this goals have an initial and final point, because is needed to have a condition that indicates that the goal is completed and the client is satisfied.
All of this concepts are useful for making the code, because you have a guide of how begin with the code and to indicate the different classes and methods you could use and the best or cheaper ways to achieve the use cases.
