Where does it come from?
How as the project initiated? Who made the decisions to start, to define the project and to identify the need and scope/?. IOW - who decided what they needed, why they needed it and how to achieve it?
This is fundamental to any project, from changing a door handle to building a new school or hospital. You could probably flow chart it.
The door handle is failing.
We need to replace it. Is the current handle's design adequate for current usage? Or is a higher specification needed. What is that spec?
Are there likely to be any new developments in door security and threats within the expected life time of a new handle and would a new kind of handle meet these needs? What handle do we need to meet these future needs?
Where can we get said handle?
What should said handle cost? What is the total budget?
Who will obtain/install......etc.
It's not rocket science.