The paper is organized into seven sections. First, we define how we measure automation in the assembly plant study. Second, we describe the overall regional trends in the use of automation from 1989 to 1993/94. Third, we explore the patterns of usage for robotic equipment across regions, emphasizing in particular the significant move by many companies towards the replacement of fixed or "hard" automation with flexible, programmable automation. Fourth, we explore departmental differences in the use of automation, emphasizing the evolution in thinking about the most effective way to automate various tasks in the body, paint, and assembly shops. While automation levels continue to rise in the body and paint shops, a different approach is being taken in the assembly department, the most labor-intensive area of the plant and yet the place where total automation solutions have been most elusive. Fifth, we describe how trends in the adoption of flexible automation are linked to the adoption of flexible work practices that seek to boost worker involvement in production-related problem-solving. Sixth, we summarize what we have learned about the performance implications (in terms of productivity and quality) of the automation trends described here. The seventh section presents our conclusions from these analyses and our speculation about future trends in automotive manufacturing automation.The International Motor Vehicle Program and the Sloan Foundation.