This study discovered that nurses experienced more than eight work system failures during an 8-hour shift. Investigators combined primary observation with interview and survey methods to understand the role work system failures play on nurse effectiveness. The most frequent failures identified involved medications, orders, supplies, staffing, and equipment. In addition to operational failures that delayed productivity, a large number of reported work interruptions contributed to the study findings. The authors advocate for continued efforts to differentiate between tactics taken by bedside nurses to prevent error with tactics that result from the system (eg, interruptions), which often put patients at risk for error.