Project Business Case
It documents the economic feasibility of the project. It is prepared before starting the project and can result in a go/no-go decision for the project. One of the criteria for determining project success. The input for Business Case is needs assessment.
Project Benefits Management Plan
It documents how and when the benefits of the project will be delivered — one of the criteria for determining project success. The inputs for Benefits Management Plan are needs assessment and Project Business Case.
Project Charter
Issued by Project Sponsor and formally authorises the project’s existence. The input for Project Charter is Business Case