Software life after in-service

Software engineers and designers tend to conclude a software project at the in-service milestone of the software life cycle. But the reality is that the 'life after in-service' is significantly longer than other phases of the life cycle, typically 20 years or more depending on the maintainability of the hardware platform and the designed life of the plant. During this period, the software asset (as with other physical assets in the plant) continues to be upgraded to correct deficiencies, meet new requirements, cope with obsolescence of equipment and so on. The software life cycle ends with a migration of the software to a different platform. It is typical in a software development project to put a great deal of emphasis on design methodologies, techniques, tools, development environment, standard procedures, and project management to ensure quality product is delivered on schedule and within budget. More often than not, a disproportion of emphasis is placed on the issues and needs of the in-service phase. Once the software is in-service, the designers move on to other projects, while the maintenance and support staff must manage the software. This paper examines the issues in three steps. First it presents a view of software from maintenance and support staff perspectives, including complexity of software, suitability of documentation, configuration management, training, difficulties and risks associated with making changes, required skills and knowledge. Second, it identifies the concerns raised from these viewpoints, including costs of maintaining the software, ability to meet additional requirements, availability of support tools, length of time required to engineer and install changes, and a strategy for the migration of software asset. Finally it discusses some approaches to deal with the concerns. (Author) 5 refs., fig