In a conventional setting, it is possible to plan activity, because the unit's management has a schedule of when work will arrive and when completion is expected. A failure-analysis laboratory cannot be operated on a preplanned schedule, because there is no warning when failures occur. Queue time can be reduced by providing sufficient resources, equipment, and staff to deal with any influx of work, but most of these expensive resources would sit idle when work is running at routine levels. A more responsible approach would be to provide equipment and staffing sufficient to meet routine work requests and accept some amount of queue time when work volume increases. It is very rare for any job to require more than two days of process time.
Queue time can be variable as a function of work load.
The customer sees the sum of the times and needs to understand why similar jobs sometime take variable amounts of time to do. Some improvement in TAT can be expected from productivity enhancements. For example, the movement from classical wet print photography to computer-manipulated digital image recording and printing significantly reduces or eliminates darkroom chores. Until just recently, results were often hand delivered locally or by overnight services for next-day accommodation of remote customers. We can now electronically transmit images anywhere in the world in seconds.