The Analysis of Alternatives (AoA) is an analytical comparison of the operational effectiveness, suitability, risk, and life cycle cost (or total ownership cost, if applicable) of alternatives that satisfy validated capability needs. AoAs are not decisional documents, but are inputs that may be used by the Program Secretarial Offices to recommend a preferred alternative. AoAs help determine the most effective approach for achieving the technical and functional requirements associated with a specific mission need, within the constraints provided. The AoA will be conducted for projects with an estimated TPC greater than $50M prior to the approval of CD-1 .