Graduate management education seeks to enhance the likelihood that graduates will be effective leaders, managers, or professionals. This requires programs that are designed to enable students to develop the related competencies, and increasing regulatory pressures require programs to document evidence of success. However, both the design of competency development efforts and the assessment of those efforts remain a challenge for contemporary business schools. Here we examine a 25-year assessment program to illustrate the challenges associated with developing emotional, social, and cognitive competencies among full-time MBA students. We discuss key interventions that yielded positive assessment results and the challenges of maintaining a longitudinal assessment data set. We then examine patterns of competency development across nine cohorts to propose five factors that appeared to affect the variations in competency development over time and cohorts: (a) sequencing effects of emotional versus social competency development; (b) the sawtooth or alternating cohort effect; (c) leadership and organizational climate in the school; (d) events in the world at large, like a global recession; and (e) program structure and design.