In the knowledge-based economy, R&D centers in service industries increasingly depend on the performance of knowledge workers to gain competitive advantage. Therefore, these centers must give careful consideration to the performance assessment and continuous improvement of knowledge workers using appropriate performance assessment systems and models. In this paper, a system was designed for the performance appraisal and ranking of knowledge workers in R&D centers of banking industry using gamification approaches. The case study method was applied for the conceptual design of the system and the selected case was the R&D center of Mellat bank, one of the Iranian leading private banks. Data collection was performed via semistructured interviews with 12 key participants of performance appraisal process which included vice president of research and development and 11 senior researchers as head of research groups of the center. As a result of data coding process for analyzing the qualitative data, a total of 23 metrics and three key performance indicators namely, research impact factor, knowledge impact factor and knowledge absorption factor were identified for the performance appraisal of knowledge workers. The designed system in this study can be used by R&D centers in banking industry for the performance appraisal and ranking of knowledge workers. The designed system provides a comprehensive and detailed set of metrics and KPIs for the performance appraisal of knowledge workers in R&D centers of banking industry.