In Computing, Turnaround time is the total time taken between the submission of a program/process/thread/task(Linux) for execution and the return of the complete output to the customer/user. It may vary for various programming languages depending on the developer of the software or the program.

Turnaround time is one of the metrics

Metrics

A metric is a measure for quantitatively assessing, controlling or selecting a person, process, event, or institution, along with the procedures to carry out measurements and the procedures for the interpretation of the assessment in the light of previous or comparable assessments.Metrics are...

 used to evaluate operating system scheduling algorithms.

In case of batch systems, turn around time will include time taken in forming batches, batch execution and printing results.