Turnaround time is one of the metrics used to evaluate an operating system's scheduling algorithms.
Laboratories may publish an average turnaround time to inform their clients, e.g. a health care worker ordering the test, after what time a result can be expected.
A prolonged turnaround time may give the requester a clue that a specimen was not received, that an analysis met with problems within the lab including that the result was unusual, and the test was repeated for quality control.
[5] Lead-time is basically the time gap between the order placed by the customer and the time when the customer get the final delivery, on the other hand the Turnaround Time is in order to get a job done and deliver the output, once the job is submitted for processing center according to the customer request.
First of all, if laborers or equipment are not working properly, and if the maximum efficiency could not be reached, the process would be delayed.