The global service robot market is projected to grow significantly, with robots promising cost savings, productivity gains, and enhanced customer satisfaction. However, their adoption also raises concerns about employee apprehension and the need for new theoretical frameworks. Utilizing the Job Characteristics Model (JCM), this research examines how robots alter work experiences, bridging the gap between established theories and contemporary realities. Two mixed-method studies were conducted: Study 1 (exploratory survey) surveyed 220 restaurant employees, identifying themes like "perceptions of robots being useful with employees" (PUwE) and "perceptions of robots being useful without employees" (PUwoE). Study 2 (confirmatory study): Validated the JCM's relevance in this context and confirmed the significance of PUwE and PUwoE with a sample of 346 employees. This research expands the JCM by revealing new dimensions introduced by robots, such as altered skill variety and task identity, and explores their psychological impact on job satisfaction and performance. It lays the groundwork for future studies on job design and technology, offering a methodological framework to examine the influence of AI and emerging technologies on workplace dynamics.