Setup Time:

Setup time is the time among when the last unit of one batch (production run, contiguous job) is finished and the primary acceptable unit of the next batch is finished. The concept of setup time applies to several activities: time necessary to changeover an assembly line; time for workers to attain minimal proficiency at doing a new job (the learning curve); time to load items, time to clean an operating room and get ready for the next surgery; transport them, then unload them; time for a manager to settle into her office, turn on the computer, check the e-mail, and do whatever else before the day's work can starts.

Though, setup time is one of the various factors that contribute to lead time. The best way to know if the right factors are being tapped to reduce lead time is to measure lead time directly.