Public authorities face significant challenges when procuring software systems that effectively support their operations and employees. The mandatory Request for Proposal (RFP) process often prioritizes cost and technical specifications, with limited attention to the usability and user experience (UX) of the new system for users. This paper addresses this gap by exploring how usability and UX as performance factors in the RFP can be systematically integrated into the tendering process for public sector procurement. Drawing on collaboration between academic researchers and practitioners, the study examines two case studies: (1) the selection of an agile development team through RFP for developing a financial support application and (2) the selection of an already developed collaboration and information management system (CIMS) through RFP for government ministries. In the first case, team collaboration, UX focus of the team, and code quality were evaluated as performance factors in the selection criteria in parallel with the estimated cost of developing the system. In the second case, the selection factors were cost and quality, including usability metrics such as effectiveness, efficiency, and satisfaction. These cases illustrate how research-practitioner collaboration can bridge the gap between academic principles and professional practices, advancing the design and procurement of software that extends the usability and UX of the procured systems. The findings contribute actionable insights into enhancing public sector RFPs by integrating usability and UX as performance factors.