Commercial off-the-shelf

Commercial, off-the-shelf (COTS) or simply off the shelf (OTS) is a term for software or hardware, generally technology or computer products, that are ready-made and available for sale, lease, or license to the general public. They are often used as alternatives to in-house developments or one-off government-funded developments. The use of COTS is being mandated across many government and business programs, as they may offer significant savings in procurement and maintenance. However, since COTS software specifications are written by external sources, government agencies are sometimes wary of these products because they fear that future changes to the product will not be under their control.

Motivations for using COTS components include reduction of overall system development and costs (as components can be bought or licensed instead of being developed from scratch) and reduced maintenance costs. In software development, many considered COTS to be the silver bullet during the 1990s, but COTS development came with many not-so-obvious tradeoffs&mdash;overall cost and development time can definitely be reduced, but often at the expense of an increase in software component integration work and a dependency on a third-party component vendor.

Defense Applications
The Department of Defense has found great potential in COTS products. As technological advances are driven by the commercial market, COTS purchases allow the Department of Defense to "entice" new companies and "capture" new innovations. By refining its COTS acquisition process, the DoD can facilitate the entry of new companies into the defense industry, thus ensuring continued innovation.

The canceled VH-71 Presidential Helicopter is one example of a failed acquisition from COTS. Based on the EH101 helicopter by AgustaWestland, an Italian-British manufacturer, the aircraft failed spectacularly due in large part to failures by the US acquisition process.