What is important when deciding to include a software requirement in a project or release?

The requirements on software systems are so many that not all requirements may be included in the next development project or the next release. This means that it is necessary to select a set of requirements to implement in the forthcoming project, and hence to postpone the implementation of other requirements to a later point in time. In this selection process different criteria are used. In many cases, the criteria are not officially stated, but rather implicitly used by the decision-makers. However, to be able to support this decision-making process, it is important to know and understand the underlying reasons for the decisions. This paper presents an empirical study of the decision criteria. In particular, the paper focuses on how different perspectives have different influence on the decision-making process. It is concluded that business-oriented and management-oriented criteria are more important than technical concerns related to software architecture, impact analysis, dependency between requirements and software evolution.