Enterprise architecture is closely associated with strategic planning or IT strategic planning. Some view enterprise architecture as planning. A common main output of the enterprise architecture activity is a transition plan (aka roadmap or transformation plan).
Examples:
Steven H. Spewak's book "Enterprise Architecture Planning, Developing a Blueprint for Data, Applications and Technology" ISBN 0-471-59985
Another book: Jeanne W. Ross et. al. "Enterprise Architecture as Strategy: Creating a Foundation for Business Execution" ISBN 1-59139-839-8
John A. Zachman: "During the 1980's, I became convinced that architecture, whatever that was, was the thing that bridged strategy and implementation".
The top policy for enterprise architecture of the U.S. Federal Government, OMB Circular A-130, transmittal 4, identified strategic planning as a direct input to enterprise architecture.
"If you do anything long enough, you eventually get good at it." MK