In the context of developing a new online student portal for a university, what considerations should be taken into account during the planning phase of the SDLC$?$ Provide at least three key elements $[5$ MARKS$]$

During the design phase of the student portal development, what specific considerations should be made for the user interface, and why is creating a detailed design crucial before moving into the development phase. $[5$ MARKS$]$

Why is thorough testing essential for the success of the student portal? Provide examples of different types of testing that should be conducted and explain their significance in ensuring the functionality and reliability of the system $[5$ MARKS$]$