5b14a17c_for_Agile_Software_Development__2
[0] Design decisions [1] Developers, Maintenance Developers, Project Managers [3] Question the need for most of this information. Are people really going to care several years from now why you did something? Focus on decisions that are not obvious, which had other reasonable alternatives, or ones where you explored what initially looked like a reasonable alternative that in the end proved insufficient for your needs. The goal of this effort is to avoid needless refactoring at some point in the future or rehashing a previously made decision. Design decisions are often documented throughout other artifacts, such as system overviews and source code, although you may choose to have a separate document when appropriate to the situation. [4] Perhaps [2] 
A summary of critical decisions pertaining to design and architecture that the team made throughout development
Agile/Lean Documentation: Strategies for Agile Software Development
2