Incorporate into Architecture Models
Architectures are created to guide an enterprise or initiative from a baseline (current) state to a target (future) state. They typically encompass a wide range of architectural levels and types from Business through to Technology Architectures and translate notions such as goals, drivers and capabilities into roadmaps that define the direction that the enterprise or initiative will take to reach its target state and as a consequence its goals. Decisions can be built into the architectural models allowing them to be visualized as part of the architecture. These decisions will typically be defined at a high level but will capture the strategic and solution level thinking that would be otherwise lost in a textual document.
Enterprise Architect is quickly becoming the industry's tool of choice for both Enterprise and Solution level architecture and being able to build the decision models into the architecture models will ensure that there is traceability from the low level implementations right back to the design and architecture levels including requirement levels.