Three questions in the field of system integration

I don’t know how to handle this Computer Science question and need guidance.

Q1- Given the following diagram, discuss the need of effective methods for software and systems integration for each phase in software development lifecycle?(digram in attachment)

Q2- According to CMMI, what is the purpose of the project plan? What are the necessary activities in planning?


Q3-What are software requirement tools? What are two major categories of these requirement tools? Write some key features that must be considered while choosing the requirement tools? Also give some real-world examples for some of these tools.


you can use the book in attachment or search for answers in other sources if this book not enough

I hope that your answer is as required in each question and is accurate

Please write by using your own words.