Bahethi RR, Gold BS, Seckler SG, et al. - Via performing a direct observational study based on lean principles of quality improvement (QI), researchers sought to determine operative workflow and efficiency in microvascular free flaps. The workflow of 23 free flaps was monitored by the observers. Record of preoperative preparation and surgical duration was maintained with supplemental data gained from the institution's surgical tracking database. Documentation of traffic patterns of operating room (OR) staff as “entries” and “exits” from the OR was done. Chart review was done to obtain patient data. The mean surgical time of 9.0 h was reported. The preincision process took nearly 20% of OR time, averaging 1.6 h per case. One third of entries and exits occurred during this period. In total, they observed 180.2 surgical hours during which 6,215 “entries” and “exits” were noted. Observations suggest that due to lengthy procedure times, challenges are faced in executing comprehensive observational workflow studies of free flaps. A significant portion of OR time is devoted to the preincision period at their high-volume institution, largely because of inadequate supply availability and preoperative communication. These findings seem to be valuable as a foundation for QI interventions at their institution, while their observational model yields a broadly applicable framework for determining surgical efficiency.