The planning of additional featuresand releases is a major concem for commercialsoftware companies. We describe how, in collaboration with Ericsson Radio Systems, we developed and tested an industrially useful approach to softwarerequirementsprioritization. Keywords Requirements,prioritizing,release planning, CONTEXT Ericsson Radio Systems AB is a leading supplierof mobile telephony software. Since 1992 it has collaborated with Linkoping University, Sweden, in a concerted effort to improve the early phases of the software engineering process. Starting in January 1994 we have participated in the requirements definition phase of a number of major projects and, through this collaborations, identified requirements prioritization as a key issue for software developers. FOCUS From the outset, it was clear that many major projects had far more candidate requirements than the company could ever afford to implement in a single release. A typical method of selecting which ones to implement was ...