Define scope is the PMI process that identifies in detail what needs to be done to complete the project. This process is in the PMI planning process group and in the scope management knowledge area.

According to the PMBOK, this activity has the following characteristics:

Inputs Tools and Templates Outputs
Scope management plan, Project charter, Requirements documentation, Organizational process assets Expert judgment, Product analysis, Alternatives generation, Facilitated workshops Project scope statement, Project documents updates

The product analysis and alternatives generation help to decide what could and what must be in the product, service, or result being developed. Expert judgement helps to elaborate the options and evaluate their feasibility. And a facilitated workshop, gets agreement and sign-off on the scope, both what is included and what is excluded.