  Requirement prioritization is recognized as an important decision-making
activity in requirements engineering and software development. Requirement
prioritization is applied to determine which requirements should be implemented
and released. In order to prioritize requirements, there are several
approaches/techniques/tools that use different requirements prioritization
criteria, which are often identified by gut feeling instead of an in-depth
analysis of which criteria are most important to use. Therefore, in this study
we investigate which requirements prioritization criteria are most important to
use in industry when determining which requirements are implemented and
released, and if the importance of the criteria change depending on how far a
requirement has reached in the development process. We conducted a quantitative
study of one completed project from one software developing company by
extracting 32,139 requirements prioritization decisions based on eight
requirements prioritization criteria for 11,110 requirements. The results show
that not all requirements prioritization criteria are equally important, and
this change depending on how far a requirement has reached in the development
process.
