Characteristics of New Requirements in the Presence or Absence of an Existing System Architecture

While much research attention has been paid to transitioning from requirements to software architectures, relatively little attention has been paid to how new requirements are affected by an existing system architecture. Specifically, no scientific studies have been conducted on the "characteristic" differences between the newly elicited requirements gathered in the presence or absence of an existing software architecture. This paper describes an exploratory controlled study investigating such requirements characteristics. We found that a multitude of characteristics (e.g., end-user focus, technological focus, and importance) were affected by the presence or absence of an SA, and the extent of this effect. The study results have implications for: RE process engineering, post-requirements analysis, and future empirical work in RE based on emergent hypotheses from this study.