sentences:  These times may not be convenient for the customer, and the contact center runs the risk of a bottleneck if the anticipated reduction in demand or increase in staffing doesn't occur.While both First In, First Out and Scheduled queuing can provide significant performance benefits to the call center, some queuing systems only allow for scheduled callbacks, though FIFO is clearly preferred.The limitations of these forced-scheduling systems do not provide an optimal customer experience, and their reliance on countdown timers or call traffic forecasts may negatively impact contact center operations.