  Requirement prioritization is recognized as an important decision-making
activity in requirements engineering and software development that 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 83,408 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.
