If the DoD gives Congress guidance on budget bands and what capabilities are given up in each band below the "ideal" band, especially in projected political ter

If the DoD gives Congress guidance on budget bands and what capabilities are given up in each band below the "ideal" band, especially in projected political terms, then I can see Congress setting a preliminary budget and finalizing after some more detailed DoD analysis of what is projected to be accomplished under that budget. For example, tell Congress for a $1B ideal budget of a weapons program, a $750-800M budget band would mean response time to deploy the weapon drops from 6 hours to 6 days. Not such a big deal for a littoral combat operations boat, but a huge deal for a cruise missile block upgrade. But we're all outsiders here, and I'd love to hear inside baseball on what the real factors are behind these procurement processes.