Laboratories often focus on computer-generated components of turnaround time (TAT) reports that capture time from sample accessioning to reporting of results, and use this indicator to determine performance. This study assesses limitations of "accessioning-to-results" times and details ways in which to evaluate laboratory-controlled TAT. Samples were sent via pneumatic tube and times from arrival to accessioning were determined. Staffing was increased and the delay between sample arrival and accessioning was measured again. Significant delays were seen between specimen arrival and accessioning, which were not captured with computer-generated TAT reports. When TAT was calculated to include these delays, the TAT goal was not achieved. Increasing the number of employees significantly decreased delays. Laboratories must ensure that TAT reports encompass all laboratory-controlled parts of the testing processes. Analysis of causes for discrepancies between computer reports and clinician perceptions, combined with targeted measurements and well-designed interventions, can decrease TAT and improve service.