Interruptions are a central characteristic of work in critical environments such as hospitals, airlines, and security agencies. Often, interruptions occur as notifications of some event or circumstance that requires attention. Notifications may be delivered actively as disruptions requiring immediate attention, or passively as unobtrusive background messages. This research hypothesizes that the way notifications are delivered can have an impact on how work unfolds over time, which in turn can affect performance. Based on theories of interruption and observations in an actual operating room, a computer-based role-playing game simulating the scheduling of surgeries in an operating room unit was developed. An experiment was conducted using the game to examine the effects of different types of notification delivery on work trajectories and performance. Results indicate that the way notifications are delivered can indeed influence work trajectories and, consequently, performance.