The United States Navy Working Capital Fund (NWCF) is a branch of the family of United States Department of Defense (DoD) Working Capital Funds. The NWCF is a revolving fund, an account or fund that relies on sales revenue rather than direct Congressional appropriations to finance its operations. It is intended to generate adequate revenue to cover the full costs of its operations, and to finance the fund's continuing operations without fiscal year limitation. A revolving fund is intended to operate on a break-even basis over time; that is, it neither makes a profit nor incurs a loss. United States Navy activities financed through the NWCF perform a wide variety of functions including Supply Management, Depot Maintenance, Research and Development, Transportation, and Base Support. The NWCF continues to pursue some important efforts to improve efficiency and maximize effectiveness. Success in these endeavors is critical to ensuring that the Department of the Navy can afford both the ongoing support costs of fleet operations and the necessary reinvestment in new platforms and weapons systems. History of the NWCF Historically, the U.S. military has had two categories of revolving funds; stock funds and industrial funds. Stock funds, in use by the Navy since the 1870s, were aimed at financing the procurement of material (spare parts and other items) in volume from commercial sources, to be held in inventory. This material was intended to be sold to customers, in order to achieve weapon systems readiness or to provide personnel support. Industrial funds, in use by the Navy since the 1940s, provided industrial and commercial goods and services such as depot maintenance, transportation, and research and development. The 1949 amendments to the National Security Act of 1947 authorized the United States Secretary of Defense to establish revolving funds as the business model for the operation of these funds. In 1991, all of DoD's stock and industrial funds were rolled into a single revolving fund, the Defense Business Operations Fund (DBOF), along with five additional defense commercial operations or business areas previously funded with direct appropriations. DBOF was capitalized at a level significantly less than the sum of the stock and industrial funds it replaced. The consolidation of stock and industrial funds caused overall cash levels to be reduced, by allowing funds or capital to be shared across all of the activities, resulting in cash flow problems. The Defense Authorization Act addressed this issue, requiring that