Which document outlines the requirements and high-level vision of an architecture?

The Architecture Vision document is the appropriate choice because it serves as a foundational piece in the architecture development process. This document articulates the overarching goals, objectives, and high-level vision for the architecture. It captures what the organization aims to achieve through its architectural initiatives, including the strategic context, business drivers, and stakeholder concerns. By defining these elements, it provides a guiding framework that aligns architectural objectives with business needs.

This document is critical during the early phases of architecture development, as it sets the direction for subsequent efforts and helps stakeholders understand the intended outcomes. It usually includes a summary of the requirements which inform the architectural work that follows, ensuring that the architecture solution remains aligned with the organization's strategic goals.

Other documents, while important to the architecture development process, serve different purposes. The Architecture Definition document provides a more detailed representation of the architecture itself, whereas the Architecture Requirements document specifically lists the requirements that the architecture must meet. The Architecture Governance document outlines the processes and frameworks for ensuring compliance with architectural standards, but does not define the vision itself.