The majority of the spending in the procurement industry is done in the last three months of the fiscal year due to the arbitrary use-or-lose budget imposed by the IRS. As a contracting specialist I see customers repetedly purchasing items they do not need (replacing working items, adding unnecessary items, etc.), senselessly spending billions so that their unit will have a sufficient budget the next year should they actually need it. Usually the next year they are buying the same sorts of things just to keep their budgets overinflated.
I propose that that the fiscal year system be eliminated in exchange for a more fluid system of tracking spending. The FPDS-NG system has already been implemented almost entirely across the DoD. In an environment of no fiscal years, using the FPDS-NG system the IRS or another agency could monitor and approve budgets on the fly, eleminating the pressure on units to spend all the money allocated to them in only a couple months (which decreases the efficiency of procurement offices dramatically, usually resulting in an abuse of Sole Source programs due to insufficient time to properly compete requirements and ensure the lowest price).
Piggybacking off of this, implementing H.R.25/S.13, the "Fair Tax" act could be used to eliminate the IRS, saving many hundreds of millions more a year and is a workable solution to assist in controling federal spending.