the Input of Communications Planing Process

The propose(output) the Communications Planing Process is to produce the Communications Management Plan...

So , Clearly , we may need the input as follow:
1. Enterprise environmental factors.
2. Organizational process assets.
3. Project management plan(Constraints adn Assumptions)
4. Project scope statement ??????
m............
But why should we need Project scope statement?
there are no clear relationship between Project scope statement and Communications Management plan


According the explanation on PMBOK P.226, it writes:

'The project scope statement (Section 5.2.3.1) provides a documented basis for
future project decisions and for confirming a common knowledge of project scope
among the stakeholders. Stakeholder analysis is completed as part of the Scope
Definition process.'

基本上，有看沒有懂，have any one a good explanation of that?

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