First thing to review, did the run create records? F3411, F3412, F3413? If
the records are there, then verify the version of Time series to ensure that
it is using a valid time series quantity type.
Otherwise, since you have checked the S&D rules and verified that the SO
type/line and status are correct, a couple other things to review are the
line type. Does the line type have an inventory interface turned on?
Another area to review is the time series Quantity Type in MRP and verifying
it against the one in the Time Series Inquiry Program and verifying it is
actually setup. Another area is to review the PN records in the Branch
Plant (Planning Code, Planning Fence and Code, Message Display Fence). Have
the low level codes been set? If running multiple runs of MRP, is the
processing option to clear the file before running turned off (opt 25 in
A81)?