The decision to work within architecture does not usually come out of thin air. It requires a motivation. This motivation could come from many sources: varying from the appointment of a new manager who believes that things could be a lot better, to an (c)overt crisis in the organization. The motivation is usually a reasonable indicator of, but shouldn’t be confused with, the objectives of using architecture. The motivation is usually symptomatic, the objective is the underlying cause that needs to be addressed. 
For instance the motivation could be that the communication between two projects is in danger of going awry but the ulitmate goal of the architecture is to better manager the project portfolio. 

It is advisable to build up the architecture vision based on the motivation for the architecture. The motivation is almost always an indicator of the pain. That pain needs remedying now and in the future it needs preventing. Should the organization be in danger of reverting to it’s old ways, it is useful to remind them of the motivation for the change. 
An illustration in the manner of: “do you remember why we started using an architecture…”