Lead Time calculation

Is there any printout or log or some other option to get the detailed information on how the Lead Time is calculated for some assembly item?

We are testing different settings for resource availability by changing Calendar, Shifts, Workday Patterns, available hours. In some cases we are not able to understand the calculated Lead Time results, and the Operation and Resource Offset%. So we are looking for some explanations. We are particularly confused in examples of multiple Shifts defined per singled Resource, or multiple workday patterns defined per single Shift.

We read the Bills of Material Users Guide and documentation available on support for this issue, but such detail can not be found there.