[1] The AoA establishes and benchmarks metrics for Cost, Schedule, Performance (CSP) and Risk (CSPR) depending on military "needs" derived from the Joint Capabilities Integration Development System process.
[2] It moves away from employing a single acquisition source to the exploration of multiple alternatives so agencies have a basis for funding the best possible projects in a rational, defensible manner considering risk and uncertainty.
These metrics help compare the operational effectiveness, suitability, and life cycle costs of alternatives to satisfy the military need.
Though Source Selection criteria change per proposal request, and specifics are considered sensitive information, there is usually some form of the Cost Schedule Performance (CSP) trade-space analysis, and strong consideration of Risk, (CSPR).
The key purpose of the AoA is to identify a "solution" that will fulfill the stated requirements as optimally as possible commensurate with established cost and schedule constraints, at the lowest practicable risk.