Agreeing on a development schedule that can't be met offers software developers and their marketing team a convenient excuse for their failures. A similar situation occurs over the lifetime of software systems. As a system ages, its design will no longer match its actual use. Also, successive generations of programmers will violate design assumptions and style guidelines. Instead of admitting the fact that the system should be scrapped, developers and their managers will often propose a rewrite on the grounds that a new technology will offer dramatic productivity improvements. This face-saving maneuver also offers a convenient scapegoat.