Software systems evolve with societal, business and technological changes. Because of these changes, socio-technical systems need to adapt to new situations that were unknown at the time of design. Good knowledge of software system evolution can help with that adaption. Although the evolution of software systems has been broadly debated, little research has been conducted on the specific genre of software systems and even less empirical research has been performed on the evolution of interactive software. We propose a three-factor framework which consists of identifying the changes during the evolution of training simulators, the drivers for those changes and how the changes effect innovation and robustness of the training simulators. In reviewing the literature on training simulators, we argue for this framework. The contribution of this paper is a framework that can be used to carry out empirical studies on the evolution of training simulators.
Interaction ScienceSoftware systems evolve with societal, business and technological changes. Software technologies are said to evolve in a Darwinian manner by co-evolving with human culture [1]. Societal changes, including the migration of people and workers, poverty, health and education, can influence how software systems evolve. Business operations and their marketplace can be drivers of the evolution of software systems. Furthermore, innovations in technologies for building software systems influence their evolution. Because of these changes, today's sociotechnical systems need to adapt to new situations that were unknown at the time of design [2]; good knowledge of interactive software system evolution can help with that adaptation. Sociotechnical systems cover hardware, software, personal and community aspects [3] and when we refer to interactive software systems in this paper, we are not limiting the discussion to the software and its users. An example of a sociotechnical system is a training simulator for managing the response to large scale accidents such as those involving aircraft or trains. It concerns the hardware used, the software developed, the trainers and trainees using the system, and the community surrounding the professions and stakeholders. The development of such training simulators is costly. Training simulators can be long-lived up to several decades and thus undergo various changes in the course of use. Examples of these are changes because of improved work processes that are discovered during training exercises or real response, or demand for higher fidelity as trainees, for example firefighters training to extinguish fires.Researchers have debated whether there exist such things as revolutionary products, or inventions, or if all are evolutionary [4, p.86], created in small steps visible only to the designer but invisible to the consumer [5, p.2]. Vicente [6] distinguished between revolutionary design and evolutionary design problems. Whereas in the former, the constraints decided on in past versions can change, in the latter, the constraints...