CrossTalk—January/February 2014 33 LEGACY SYSTEM SOFTWARE SUSTAINMENT

Abstract.Today’s systems are increasingly reliant on software which must be sus-tained into the future. To sustain these systems organizations must define sustain-ment, meet criteria to enter sustainment, and overcome some classic sustainment challenges. This article discusses these tasks along with historical parallel develop-ment and sustainment and potential future trends in software sustainment. Software Sustainment Now and Future While DoD Instruction 5000.02 describes sustainment in de-tail, no authoritative definition of “software sustainment ” exists. The SEI’s working definition is as follows: The processes, procedures, people, material, and information required to support, maintain, and operate the software aspects of a system. Given this definition, software sustainment addresses other issues not always an integral part of maintenance such as documentation, operations, deployment, security, configuration management, training (users and sustainment personnel), help desk, commercial off-the shelf (COTS) product and license man-agement, and technology refresh. Successful software sustain-ment consists of more than modifying and updating source code. It also depends on the experience of the sustainment organization, the skills of the sustainment team, the adaptability of the customer, and the operational domain of the team. Thus, software maintenance as well as operations should be consid-ered part of software sustainment