Agile Forward-Reverse Requirements Elicitation as a Creative Design Process: A Case Study of Illimitable Space System v2

Illimitable Space System v2 (ISSv2) is a flexible and configurable multi-modal interactive system that serves different entertainment platforms and computing environments. It is a configurable artists’ toolbox for use in performing arts, music visualization, and interactive documentary creation. The output, be it in visual, sound or haptic form is primarily controlled by motion, and gesture, and voice, but also generalizable to other sensor input methods. From the design perspective, ISSv2 is an improvement over its predecessor, ISSv1, previously used likewise, for real-time motion-based interactive applications. ISSv2 is a multidisciplinary project with contributors from computer science, software engineering, computation arts, design, and others. The design requirements process which was followed for both versions was primarily demand-driven, agile, and sometimes ad-hoc in a goal oriented manner by targetting specific public events, stage design as a part of the environment, and technological and time constraints overlayed on the decision making process. As a result in this work, both versions get their requirements reconstructed in a more formal manner, albeit woven with the creative process and practices, to ensure the sustainability and maintainability of the system for future versions and deployments. This paper presents the results of this reconstruction of the functional and non-functional requirements of ISSv2 as a creative reverse design process and co-relates it with various methods, strategies, research and analysis based on design theory. The idea being that design and specification of other creative systems in the perfromative arts domain will be similar. Thus, the process can be generalized beyond the ISSv2 and serve as a guideline for future interactive real-time entertainment systems design. We summarize the process model and provide a summary of typical software engineering artifacts which evolved during the development of ISSv2. We also include a comprehensive background section on the ISS and the associated design theory for the article to be self-contained.